TEMPORARY JUMP FIX

Note, this fix shouldn't remain. Im not sure how the room manager
changes made it so that velocity is perpetually 11 on the ground, or why
gravity seems so much higher now, but we can atleast jump to test
kevin's monsters.

matt, it's posible you changed the order of things. it has to be
gravity, platform detection, user input. you might have made it gravity,
user input, platform. that'd explain it.