The concept of the game is really cool. Good job! As other people are saying, it's a bit annoying having to wait a whole 30s once you have figured out the mechanic. I suggest you add a secondary mechanic that would let you skip this time.

Cool concept! Well done :)

Good game and art! I found annoying that you have to wait 30 seconds every time you need to do something.. I think every 5 or 6 seconds could be better.  But that's something that can be done easily, great job!

Not bad, i really like the idea but maybe you should either be in control of changing the gravity or (much better i think) it changes much faster and maybe in random time intervals ... I think that would really add some more chaotic aspect, because as it is now, you just stand around for a lot of time waiting for the 30 seconds to pass so that you can go further. 

But anyway, nice idea!

Art and sound are both very pleasing. The idea is nice, however, I think changing the gravity every 30 secs breaks the game flow a bit. I mean, in order to solve some stages where you get to press a button with a box you might need to just stare at the screen for a minute or two. Apart for that, very well done =)