[krapp]

Please change your jump controls. Having the same keys for walking also jump when double-pressed makes twitchy platforming really difficult (especially given how loose the friction seems to be) and not in a good way.

Typically I've seen the spacebar, up button or W used for this. In terms of mechanics It's just adding y (or -y, whichever is up) to the player's velocity vector after a ground check.

Otherwise, good job.