Here are some things that I have noticed in the game. You may already know some of these. When I can, I'll try to get footage for them, but for now you'll have to trust me.

Pipe Clip: If you jump into the bottom-left of a block (or the bottom-left of the top part of a pipe) while facing left, you can teleport through it. An easy way to test this is to go to Level 1 and jump leftwards into the bottom-left of the fake question block at the start. An application of this would be getting onto the first hidden block in Level 3, but it is so precise that it isn't even worth trying it. It may also speed up Level 4 if you jump from the firebar and clip through the block on the right.

Instant Jumps: If you hold the up button during the lives screen, when you spawn in you can jump immediately. This doesn't have any time-saving applications, but it can be done in Level 4 OoB and no time is lost.

Infinite Mushrooms: In Level 1, there is a hidden block that constantly spawns purple mushrooms. If you hit it multiple times, the rate of spawning increases.

Level 4 Warps Softlock: If you go to level 1, hit the block under the checkpoint, get the checkpoint, then warp to level 4, you will be stuck inside the floor. :(

Enemy Clipping: If an enemy falls onto your head, you may get pushed into the ground. As far as I can tell, this is completely useless.

Flagpole Observations: -It is faster to hit the bottom of the flagpole in a run as the ending animation is faster. -Facing left before hitting the flagpole drastically slows the ending animation. -In level 3, you can cancel the ending animation if, after the enemy throws you, you jump back. This also stops the flagpole from functioning properly.

More level 4 softlocks: -If you go out of bounds and go to the very end of the level, you get softlocked. -If you go over the flagpole and keep going, you get softlocked.

Instant Pipes: Go to any sideways pipe, such as the one in the first section of level 2. To the left of this pipe is a hidden block. Jump against the right side of it, and then when you're standing on the pipe hold down. You should be hidden behind the pipe. Then, tap right and you will immediately be shot out of the pipe. This could save a small amount of time, but to line it up properly without the hidden block may be TAS-only or even impossible.

Wall Jumps: -In level 2, go to the underground area and scroll the screen right until there is only a small amount of the left wall visible. Run and jump into the wall, and you will be standing on air next to the wall - you can even jump off this air. This works on any right-facing wall. This isn't very useful, but it's an interesting glitch. -Also in level 2, where the crowned enemy blocks the path, you can hit the question mark block that spawns the mushroom that makes the crowned enemy big enough to break through the floor. If there is a 1-block gap created in a wall, you can run into it while holding jump to jump off the wall.

Offscreen deaths: On Level 2 and 4, if you go out of bounds, there is a chance that you may die if you jump to your full height. I don't know why this happens or how to do this consistently, though.

Shell through block: In level 2, make the shell enemy go to the right so it hits the hidden block. Stand in the middle of this block and the shell may go through the hidden block.

Crushed enemies: If an entity lands on another entity, it may push it through the floor. For example, in level 6 the falling blocks can crush the enemies. Sometimes, a result of this is an invisible enemy that can still kill the player.

Fireball Pipe: In level 2, even if the green circle has been hit, it is still possible to get past the pipe that spews fireballs.

Level 2 softlock: If you get a checkpoint in any level and warp to level 2, you will notice an empty area with just some random blocks. If you get the 2nd checkpoint in level 3 then warp to level 2, there is no way to escape, so you get softlocked.

Jumping off dangerous blocks: -You can jump off the blocks that break under you when you step on them. -You can jump at usual height on the springs that usually send you off the screen. -You can jump off firebars if you do it properly. -You can stand on (and jump off) the fire that appears in level 4 after the checkpoint. -If you somehow had invincibility, you could bounce on lava.

Standing on air: On level 3, there is a block to the left of the shell enemy. If you hold right, you can stand on the air next to it.

Despawning enemies: On level 4, sometimes some of the crowned enemies despawn.

Death Pipe: If you die during the pipe animation, you lose a life after you enter the next zone.

Mouse Only: Any% is definitely possible with an on-screen keyboard, though it is VERY difficult as you can only do one input at a time.

I'll be sure to get footage for these as soon as possible.

Hi, I am new. But also you can use the firebar jump to get oob on level 4 if you let the second firebar after the checkpoint go past the spike block and jump on it at the right time. It is useless for speed runs since the other way is faster, but just a neat little thing. (You are a god btw SP)

Oh and also, (completely useless) If you go oob above the final tube in level 2 and get to the fake warp room, then try to jump further to the other side, you will die consistently