Autojump: After jumping, release jump and hold it again. You jump as soon as you touch solid ground again.

Brick clip: Presumably, you can jump if there are no bricks in a specific pixel above you [citation needed]. Conveniently, you can stand on bricks if any part of the bottom of your hitbox is touching ground. This enables you to jump up bricks directly above you unhindered and climb to the top, like a most agile squirrel dude.

Dying: Done frequently in speedruns, this tech enables you to return to the starting point of a level at the cost of all level progress. (Minor note: there is no benefit to this)

Vine/chain movement: climbable things snap you horizontally to its position if you press or hold up as you touch them. You can use this to move horizontally faster, or avoid this as desired. It also behaves as a floor, but not a ceiling, so you can jump off them at any point. It’s usually preferred to jump as you climb, as the vertical speed is faster than climbing alone. The bottom can also pull you up onto platforms normally out if reach in some cases.

Ice cream/froyo/chalice thingy: Good luck.

Those dude that carry you and move at bogus speeds: You can sometimes break out of their grip???

General life advice: Be excellent to each other, and party on, dudes!