arrow keys, doing things this way is better because of bad slope detection and such, the way we did it before was so bad it wasn't funny, it broke all the time, you got stuck on slopes, and things like that. this is an updated version of @griffpatch_tutor 's platformer engine stripped down to basically nothing, but it makes slopes function better. use the slider to see the old version, which is very jumpy and scales the height of the slope you can go up to your speed (not good)
