General comments:
This run is played with the GCN GBplayer which has the bad habbit of giving some input lag.
This results in some bad timed jumps and hitting of enemies in obvious places. As far as I know there's no way
to counter this for older gb games and makes the run look sloppy at times. Unfortunatly there is no (easy) way to
directly capture images from the GBA.

A second note is about the game itself. KDL1 is speedrun-hell for 2 reasons: Huge amounts of RNG (the boss fights)
and seemingly random slowdown everywhere which can cost you several seconds in a run.

Other than that I can say I got relatively lucky with the boss paterns overall in this run
culminating in a very fast DeDeDe fight.

Individual stages:

Stage 1: Green Greens
The first area up to the mini-boss goes as planned, only the final bomb animation of Poppy can be slightly faster.
The route I take after this seems to generate the least amout of slowdown while maintaining my speed to the right.
Inside the tree everything goes well up untill our first display of RNG: Whispy does the short gust animation twice
(while 0 is possible).

Stage 2: Castle Lololo
The entire stage up to Lololo & Lalala goes very well. The boss itself is a different matter: this is by far the hardest
boss in the game, especially with the GBplayer. I manage to finish them off in 5 cycles, while 4 cycles was definitely
possible with this pattern.

Stage 3: Float Islands
I make the most obvious mistakes in this stage, I fail the timing of 3 jumps in the first area
(step after first cannon and 2 enemies) but this loses 2 seconds at max.
In the cave there is a minor hiccup at the first destructable wall, all else goes well.
On the ship I do a small damageboost off the cannon and finish the level in a near perfect way.
I fight Kabula at point blank to speed up the fight and grab the star on the first frame it appears.

Stage 4: Bubbly Clouds
Again I get hit in the first area, but the time lost is minor. The exploding Scarfy in the second area gives me
a damage boost. The rest of the stage including mini-boss go as planned.
Then there's Kracko, a.k.a. "the runkiller". This boss alone can cost you over 30 seconds! I get relatively lucky
with the Waddle drops, getting one every cycle and even a double one.

Stage 5: Mt. DeDeDe
Here you get the fight all four bosses all over again, including their lovely RNG.
Each boss also has it's own mini-stage leading up to them.

Lololo & Lalala: Mini-stage is as good as perfect. Again I 5-cycle the boss, which was probably the best I could've
gotten out of that pattern.

Kracko: Mini-stage is a freefall, just don't hit anything. After that you get an RNG encore with more potential waste of time.
I get a pretty good pattern here with both a double and even a triple Waddle drop at the end!

Kabula: The small pause at the stairs is intentional so I can jump the gap directly without getting hit, the float right
after that is a small mistake again. It's possible to enter the protected door with damage boosting (saves like 1s)
but I prefer a few extra hits to take on Kabula and DDD. In the clouds I just run into the snail.. Either my jump didn't
register or that was a complete brainfart. Kabula isn't as fast as the first fight, but still good.

Whispy: Mini-stage is (near-)perfect. Again Whispy decides to spit twice unfortunatly.

DeDeDe: The last great stand of the RNG beast: King DeDeDe. If you stay on the ground he can either hammer (star),
groundpound (star), bellyflop or suck. Sucking is the worst that can happen because it's quite a long animation.
In this fight I get a near perfect pattern of hammers (the fastest animation that gives stars). I mess up one jump
and make him do an air-hammer which wastes time. Taking damage does nearly nothing to your time
except maybe a few slowdown frames. This was one of the best DeDeDe patterns I've ever had.