Fun game. I like the simplistic presentation, with the electronic tune and the pixelated graphics, I just wish the music would change a bit more during the stages.
The gameplay concept is easy enough to understand, and it's pretty cool, although I do believe I have already seen other flash games with this exact concept, I just can't quite remember. While it's mostly simple to understand how the game works and the character moves, the controls are a bit confusing. You see, my instincts tell me to move the character with WASD, yet all that accomplishes is changing the direction of gravity, so I have to focus on the d-pad and then, whenever I press WASD again, I just proceed on using WASD until I remember to focus on the d-pad again, which becomes mind numbing quickly (maybe add an option to change the two around?). One thing you did right with the controls, though, is that the walking directions are relative to the screen, not to the character, which helps make movement a lot less frustrating in parts where I'm supposed to walk around in many different gravity directions in succession.
The stages were not bad, they were well designed and fun, save for a few frustrating moments (e.g. getting the stars in certain levels were you have to change gravity in midair), and I also love the references to other games such as Tetris and Flappy Bird. So, overall, the stages are nice.
With that said, I think it's fair to say this game is pretty enjoyable, even though its concept does sound familiar for whatever reason (not that this is a bad thing, two different games having similar concepts doesn't imply any kind of ripoff, only maybe a clear inspiration).