This run is done on version 1.2.2, using Artifacts. 1.2 fixed the previously used wall-dashing glitch, but it comes with some useful features of its own. Most obviously, the resolution is scaled, giving significantly greater view over the map, which makes finding teleporters a lot easier.

The new Any% speedrun still uses the same three artifacts:

Command: Items spawn as crates, instead of randomly, allowing you to pick your own upgrades. More on this later.

Glass: Increases your damage by 500%, at the cost of 90% of your health.

Spirit: All characters gain increased movement speed as they take damage.

Since wall-dashing was fixed, the Mercenary is no longer the fastest. Instead, the Bandit has become the most useful, thanks to a glitch that I start activating in the first level. As before, a Dried Lake start is required for the quickest portal, but now it's also mandatory to get an orange item drop as quickly as possible. The Gigantic Amethyst, a new item in patch 1.2, gets the fun started.

The Amethyst resets the cooldown on all skills. For the Bandit, this gets some interesting results. Using Smokescreen, which turns him invisible and gives bonus movement speed, then resetting cooldowns and using it again, will stack the movement speed permanently. Infinitely. This we call the Bandit Sprint. It doesn't take long to zoom across the map at insane speeds.

I keep stacking the Bandit Sprint until my character becomes nigh uncontrolably fast. There is such a thing as going too fast, as it can become really difficult to do proper platforming.

Once the Bandit Sprint is set up, most of the run is basically as usual. Finding portals as fast as possible, killing enemies fast, and gathering the required items. The item list has changed quite a bit as well, for reasons that'll become clear on the final level. For now, the feathers are used to help platforming, while the rest of the items are just about optimal DPS.

The Carrara Marble helps speed things along by allowing me to pick optimal locations for enemy spawns. Due to the increased resolution, enemies can also spawn a lot further away from you. If they're able to spawn above or below you, you can potentially waste a lot of time chasing after them. So I tend to pick an area where that won't happen, then use the Marble to teleport straight to the portal once it's open.

You'll probably notice that the portal spawns in every level were exceptionally lucky. Both Hidden Valley and Magma Barracks can waste loads of time with suboptimal spawns, and these locations were just amazing. Then, the Temple map not only gives me a decent spawn, but also two sacrifice shrines for an immense speed boost that also both drop items. Not only is my time insane now, my stack of items is also much bigger than usual.

But it could all be meaningless when the final level, Risk of Rain, starts. Before anything else, the game has a 50% chance to kill my run instantly. See, all those double-jump feathers I picked up give me just enough jump height to reach the top of this level, and to just fly around the first 30-second door timer. But only two of the four spawn points have an opening. I spawned in the slower of the two, but that's not really much to complain about.

After flying over the entire map, it's time to skip the other 30-second doors. Creditto Penguinguy for finding this glitch: Activating the Marble while holding Up causes me to grab on to any ladders in between me and the marker. This teleports me straight into Providence's room, saving a minute.

Then, I manage to spawn Providence with 8:59 on the in-game clock. This is significant because at 9:00 the game increments its difficulty (shown on the bar in the top-right), which would give him a higher HP pool. Had I been a second slower at any part of the game, I would've lost a good 10-15 second in killing him slower.

Finally, in patch 1.2.2, Providence forgot how to use his damage shielding. Normally, at 66% and 33% remaining health, he reduces all incoming damage to 1 for a while. Without this limitation, I can gear my item layout to the highest DPS possible: massive attack speed, some crit chance, and loads of rockets.

Because I never pick up an Infusion or any other health buffer, Providence can actually one-shot me. This makes the fight extremely hectic and dangerous, as a single mistake will kill the entire run. Especially during the third phase I try to balance safety and speed as best I can. Suffice to say, I didn't die, so I'm fine with it.

End timer: 9:31

RTA time: 9:36

Version 1.1.2 of Risk of Rain introduced Artifacts to the game: optional modifiers meant to enhance the difficulty and gameplay. Of course, for speedruns, they managed to make everything easier.

The new Any% speedrun uses three artifacts:
Command: Items spawn as crates, instead of randomly, allowing you to pick your own upgrades. More on this later.
Glass: Increases your damage by 500%, at the cost of 90% of your health.
Spirit: All characters gain increased movement speed as they take damage.

With the Command artifact, the majority of item RNG is eliminated. Every boss and every chest always drops something useful. It took a while to figure out the optimal item build, but it has turned out to be the following (in order of importance):
White items: Up to 6 Goat Hooves, 1 Barbed Wire, 1 Rusty Knife.
Green items: 1 Infusion, 1 Leech Seed, 1 Infection, 1 Overcharger, X Missiles.
Red items: 1 Thallium, X Tesla Coils.
Use items: If early, Carrara Marble. If late, Glowing Meteor.

This item build serves two specific functions, the first of which is related to the chosen class: The Mercenary has a dash ability, which scales in distance based on your movement speed. Once this gets high enough, the collission detection fails and allows you to dash through walls. Conveniently, 6 Goat Hooves give you enough movement speed to achieve this. Using this glitch saves at least 60 seconds not having to wait for the doors in the final level.
Secondly, a big chunk of time in the run is still taken by the Providence fight. 500% damage increase helps a lot, but Providence uses a protective shield that reduces all damage to 1. However, damage-over-time effects ignore this shield. This includes the area damage of Tesla and Barbed Wire and such. So to continuously do as much damage to him as possible, I try to get one of every DoT effect.
Of course, the Glowing Meteor is still used to one-shot the second phase of the fight. It's less important than in Vanilla%, but it's still the highest time gain on a use item.

Dried Lake:
In the new Any%, I budget myself 30 seconds to find every portal. This puts me at 2 minutes per level, a 10 minute entry to the final level, and hopefully a sub-12 Providence kill. That's the plan, anyway.
I always reset the first level to be a Dried Lake, as the Forest map is twice as large making it very unlikely to find a fast portal there.
I always try to damage boost (i.e. get hit on purpose) for the movement speed bonus of Spirit, it usually saves a decent amount of time.
Goat Hooves are the most important items to start a run with, as they're the only item that help you find portals faster. So I go out of my way to search for more small chests to get them. It was a pretty risky move, actually, but it paid off well.

Sky Meadow:
Good level, not the best layout or spawn location. I check along the bottom, despite that route being slower, because the game hides the portal in that little corner far too often, and it would've been a really fast portal if it spawned there. Instead, I get a 2:25, which is acceptable (and worth noting that without my goat hooves, that would've been at least 5 seconds slower).
I start spending my first extra Green drop on missiles. There are only 4 green items vital to the itembuild, and it's pretty safe to assume you'll get one in each level at least. Missiles have the highest bonus damage per slot for green items, and the added utility of being able to find and damage mobs anywhere on the map. So the earlier you get them, the higher the odds they'll save time.
I could have gambled for another potential item drop, but I was hoping to find a chest to the left side, and when I didn't I just wanted to not lose time exiting the level.

Ancient Valley:
All variants of the third level are very hit-and-miss. Ancient Valley has the fastest good spawns, but really slow bad spawns. Here I spawn in the middle, meaning the portal could be literally anywhere, so I jump down because falling is faster than climbing. I got really lucky, many runs die on this level.
Something I haven't mentioned yet is enemy spawn manipulation. You can lose a lot of time simply by having enemies spawn in inconvenient locations, or worse, off-camera. You want to be able to activate the portal the second the timer ends, and seeing a '2 enemies remaining' popup usually means an immediate reset. To avoid this, I try to hang around places where mobs always spawn closeby, and any area (like on the right side here) where mobs can spawn in bad locations I try to exit ASAP.
There is an element of risk/reward to exploring more of the map to find more chests, versus risking enemy spawns. It's always a judgement call based on how well my item build is progressing and how bad the spawns can get on a certain map.

Magma Barracks:
It seems like every time I make the mistake of falling to the bottom of this level, it turns out not to be a mistake. I'd estimated the portal to be on the right side of the map, but instead my mistake leads me straight to a really fast portal.
Most people really hate the Cremator. The reason is, well, obvious from the part where he nukes me down to 9 hp. The reason I hate him is because he forces me to travel so far along the map, risking bad spawns.
And a bad spawn is exactly what happens at the end. Remaining Enemies: 1. Luckily, my Missiles prove their worth, kill it off-screen, and allow me to proceed with minimal time loss.

Temple of the Elders:
At this point, I'm a little worried about this run. Only 5 goat hooves, no use item, no red items. Without the portal luck in the last two levels, this would've probably been a bad time.
Luckily, I get a red from the imp, and a use from a small crate. Unluckily, there are no chests in this vicinity, so I'm stuck using these roulette items. I'm really, really awful at using these. The first one could've gotten me a Hyper-threader; the second, admittedly, not much good. At least I didn't throw away my 6th goat hoof, but it sucks that I didn't get one.
Always remember to hit Q on the big portal.

Risk of Rain:
9:30 Risk of Rain entry. That's kinda insane.
5 goat hooves is just enough to dash through the first door. It's not enough for the second door, that's a bit thicker, so I'll have to take some damage to activate Spirit for that final push. Luckily I get really fast spawns, so it only loses me a second or two.
Now all that's left is not choking on Providence. Even with all the bonus hp off Infusion, I'm only at 230 hp, and Providence hits for over 150. Not dying isn't that hard, but not dying whilst doing good damage is.
The first phase is pretty straight-forward. Providence always attacks in a pattern of 3 slashes, 1 burst, and after repeating it 3 times, he channels his... laser bomb thing. The Mercenary can dodge his slashes while staying in his hitbox, allowing optimal Barbed Wire/Tesla DPS. Problem is, as his health gets lower Providence starts attacking faster and eventually my cooldowns don't allign with his slashes anymore. This happens earlier than I would've liked this fight, but I handle it decently enough.
Phase 2 is killed by the Glowing Meteor. Not perfect, but close enough.
Phase 3 is where things get difficult. The robots at the start are a minor annoyance, the real difficulty comes from the shadow he summons. It deals the same damage, its pattern is individual from Providence's, meaning I can't possibly have the cooldowns to dodge everything. More importantly, killing the shadow doesn't help me, I want to deal my damage to Providence. The balance of not dying and doing good damage is very difficult here, but they played along for once, and Providence dies just before the 12 minute mark.

I think it's easy to see how this run could be beaten, with just a little more luck and a little better execution. But after hundreds of resets, it's the best I could achieve, and I'm pretty proud of it.

Ingame time: 11:50
Real time: 11:54
(We've started counting in real time because of a glitch that ruins the concept of IGT runs)

General info:
Speedrunning Risk of Rain is a giant RNG troll-fest. To make things quick, here's a quick sum of everything in this game that is randomly generated and affects the run time:
Level type. Level layout. Spawn location. Location of the portal. Location of items. The items themselves. Enemy spawn numbers. Enemy spawn locations. Enemy spawn types. Enemy spawn timing. Frequency of "elite" mob spawns. And lastly, some items have %-chances to activate, and most attacks have a damage range.
To make it all sound a little less awful, there are three major elements determining the end time. The first is how fast you can reach the portal in every level. The second is how fast you can clear all the enemies once the portal has spawned, allowing you to proceed to the next level. Third is your total DPS output on the final boss. Out of these, the first two are the most player-influential. The third is the biggest time saver.

Class: Huntress is the fastest class, period. Some runners still cling to using Acrid, and he is generally more reliable in reaching the final level, but he has neither the mobility nor the consistent damage output Huntress has, in any situation. Huntress is master race.
- Abilities: Huntress is the only class that can fire while moving. She has a glaive that bounces 3 times, an explosive shot that deals aoe damage, and a short-range Blink. Blink makes her the fastest moving class of all, while her aoe is very competitive.
Difficulty: Downpour is the "standard" difficulty. Drizzle is just too easy (and the game doesn't register unlocks in it), while Monsoon is another category onto itself; portal events take 30 seconds longer on Monsoon difficulty by design.

Level 1: Dried Lake
The best level type with the worst level layout. For the first level I have a distinct rule to never accept a portal activation after 30 seconds; the fastest I've ever had is 8 seconds, while ~18 seconds is easily plausible. In addition, I generally want to pick up at least one significant DPS item here, if possible.
Honestly, this level went awful and I have no idea why I didn't reset. My item pickups were decent, two good DPS items and a reliable healing bot, but my positioning was downright moronic. I let so many mobs spawn in inconvenient locations. And then in the final few seconds the game trolls me by spawning a final wave of Lemurians right where I'd just left. I should've reset, but the exit time turned out to be decent-ish, so I decided to keep going.

Level 2: Damp Caverns
A rather awful level type. No matter where you spawn, you can never say with even the slightest security which direction the portal might be. For most levels I've learned to estimate and increase my odds, this level simply won't allow it. Thus I switched my tactic to just scout only the bottom half of the level, and reset if it's not there. Luckily, it was there, and pretty close as well. 2:30 activation is actually a very good time.
The positioning was also really nice. A number of items nearby and no potential to troll me with bad spawns. Only sad that the game decided to spawn so few mobs in general, though I ended up getting all the items I wanted. Speaking of item pickups, I get the Guardian Heart as one of the best survivability items, and just by the end I remember that one chest up there, which freaking saved the run. Lost Doll. Fuck yes.
The Lost Doll deals 500% of my max HP in damage to a single target, at the cost of 25% hp. That's a massive nuke, on a 45 second cooldown. And it synergizes wonderfully with Guardian Heart, as the energy shield will tank the health cost!

Level 3: Ancient Valley
The third level really has no good options. Sunken Palace is awful because there's only one path around the entire level, meaning a bad portal spawn or even a single enemy surviving in a bad location can cost minutes' of time. Ancient Valley isn't that much better, however, as its two main layouts are entirely different; one has a bridge overhead, the other has a large room to the west. Again, I've resigned to simply going past the ground floor and praying to RNGesus.
Thankfully, the portal was nice to me and I reached it within 30 seconds. The rest of the level wasn't quite as nice, though. Not many item pickups, of which only one is significant (Leech Seed being another awesome survivability item). Worst, the game decided to spawn a metric crapton of golems, which are both tanky and immobile (a downside because it becomes harder to AoE them down). I should have made more liberal use of the Lost Doll on this level to save a bit of time, but it can be risky to keep using it.

Level 4: Hive Cluster
Hive Cluster also only has one path that runs through the entire level. It also has actual platforming. But at least it doesn't havea single run-killing boss spawn, so as long as the portal plays nice, I'm okay with it.
And then I almost ruined the run by accidentally falling through a hole. God, this game. With only one option left I scouted out the west side of the ground floor, and lo and behold, the portal. Better yet, not a single mob had spawned upstairs. This run should've been over but it just refused to die.
Sadly, only a single item drop. At least it's a useful one.

Level 5: Temple of the Elders
The 5th level is always the same type, just two different layouts, but without much consequence to them. The portal location can be pretty bad, and in this case it definitely was the longest time waster in the run. But at least I found it and the position for killing things is good enough.
And then the little piggy gives me a Plasma Chain, and the run is complete. I kinda screw up the gambling machine, I should've just taken the drill immediately, but infusion has its uses still. Being able to afford two drones at this late stage is also really great.
Exit time: 11:00. Not the fastest I've ever gotten, but certainly a stellar time.

Risk of Rain:
Great spawn location, because it gives me a golden chest. The keycard can access one of four areas in the ship that can offer some useful support for the final boss. As the Huntress, you can get one of them while waiting for a door timer and only lose a few seconds, making it entirely worth using.
Then comes the Providence fight. Time for some explaining.

Providence, the final boss, comes in three phases:
- In phase 1, he has a few basic attacks, all of which are dodgable if you react well. Oh, and he has 26500 HP. My basic attacks hit for around 50. And yes, that's only the FIRST phase.
- In phase 2, he splits into two worms which ignore collission and have pretty weird pathing. One occasionally fires a tracking laser, the other occasionally fires waves of bullets. Both these worms have 18000 hp. But, like all worms in this game, their bodies are separated in segments, all of which can be hit by a single AoE attack.
- In phase 3, he returns to his first form, with another 28000 HP. However, he also adds two defense bots to his arsenal, and when he reaches certain health thresholds he summons a shadow of himself, which uses most of the same attacks but acts separately and is randomly invisible.
Let's just round that all up to a staggering 100.000 hit points. Did I mention that my basic attack hits for around 50? This entire fight can take over 10 minutes without good item pickups and that's only if you don't have to run away to heal.

Luckily, I have items. And they're amazing.
1. Lost Doll now deals around 2400 damage per use. Its cost is tanked by Guardian Heart.
2. The keycard bought me a Railgun. It deals 3000 damage per use, but has a very long cooldown.
3. Two turrets add a huge amount of damage. Sadly, they tend to tank Providence's attacks, so eventually they do die.

4. Plasma Chain can harm every single segment of the worms that it passes through, easily reaching 200 damage per tick.
5. Ukelele procs on the segments as well, dealing a good ~150 damage per proc.
6. When I get low on health, the two Dead Man's Feet start dropping land mines, which hit every segment they get in contact with.
(To be honest, I didn't really like the Lost Doll before this run. I preferred the Glowing Meteorite usable item, because it treats the worms' locations rather weirdly and often spawns its explosions right on top of them, which can pretty much one-shot them and end phase 2 in seconds. But really, I doubt whether it would've saved as much time as the Lost Doll has.)

7. The two robots that spawn at the start of phase 3 drop gold. Because I have Smart Shopper, they drop a LOT of gold. 5000 freaking gold, in fact. That's enough to repair my attack drones 3 times over the course of the fight.

Conclusion:
17:48. The game offered me the greatest RNG I'd ever received, and I turned it into this run. My original goal when I started grinding the hell out of this game was sub-19. Instead, I get a sub-18 IGT. I couldn't be more thrilled.