Nice idea to switch the gravity on and off (btw, initially I thought you got the same idea as me xD). I wish there was more stuff to do (maybe a storyline or something) but I agree that it's hard to do much in 48 hrs.
Minor issue I found: it was not obvious that these sparks kill me. I think they could be bigger or something to separate them from just decorative particles.
Other than that, nicely done!