When I press play, the game freezes. Using Firefox 22 with up-to-date flash.

Fun for a little bit, by the time you pass the 5th checkpoint, it's no longer enjoyable. The double jump sensitivity is badly broken, when jumping sideways, it's maybe a 30% chance that your double jump will activate, otherwise you die over and over to faulty controls. Right after you learn the walljump there is a vertical section with three damage stars, the third one is completely impossible to avoid, and the damage you sustain makes the following section extremely difficult because you can't even figure out where you're supposed to go. There is no safe spot to stand and look at the screen for a second, so you just have to keep dying and doing that stupid walljump climb over and over for a brief glimpse at the next screen until you figure out a route to take. There's hard, and there is "suffer my poor controls and unfair level design" hard, which are not the same thing.

nigh fucking impossible!

for some reason i cant play it

did know what i was gonna get ,, but this game is great its a real good rage game
music: love the music its long enough so it does not get repetitive to qucikly
art: love it
controls: easy,, btw i love the sound it makes when he jumps
game-play:,, really fun and addicting,, although i noticed after jumping onto a platform your little guy slides a little but really the reat of the game is great