Again a to short platform game...

It needs to be called: Way too short platform game. not to.

great, but sometims i fall through the floor

3/5

http://www.kongregate.com/games/rute25/again-a-way-too-short-platform-game is a bit longer

Not that bad, really... About the bug: it probably happens because your gravity keeps increasing even while you are touching the ground. Set gravity to 0 while touching ground (note: unless you want your character to be able to jump in midair, you need to set a "touching ground" condition to the jumping)