Arrow Keys to move
Up to jump obviously...
Down to crouch, also puts you below a semi-solid if on top of one.
Space (while holding an arrow key) to dash in that direction, including up/down!
Ctrl (while holding left or right) to slide in that direction.
Shift to cancel any dashing or sliding
Boss Controls:
Dash horizontally into the boss while idle to knock him over, then Down Dash into him to damage him. Damage 3 times to defeat him.