Space + any arrow key to boost in direction of desired arrow key. This doesn't have a limit at all, but I might change it. This was originally a "The Sky Crystals" (My Platformer) texture hack-ish thing, but meh. It's now an unofficial crossover with one of the best games ever and combining it with a mere scratch project's limits.
To myself, but that is useless. Possible credit to Matt Thornson for creating Celeste with his friends, it's a great game and has a spot-on soundtrack. Notes: There is no challenge yet. Diagonal dashing seems impossible. No ripped data from Celeste exists in this project. I SOLEMNLY SWEAR. This is considered to be in a beta stage. It will not be in TSC, as its a what if scenario.