This game is just awful. I played through the first 20 levels in about 30 minutes before I couldn't take any more. And I'm a completionist who hates leaving games unfinished.
First off, the in-game graphics are bad, it's hard to see what things are, or which way the blue and red streams are flowing (it's not always the same way)
The controls are terrible and very floaty. The acceleration of your Gravi is already very tempermental (moving one platform at a time to avoid spikes is nearly impossible, and the fact that it changes a lot more (read: becomes worse) when you shoot your matter out, makes attempting complex series of moves in a time limit (like after hitting a switch) terribly frustrating.
The menu screens are also poorly designed. I understand you want to keep the mechanical aesthetic, but when I can't figure out where the buttons are to change screens or close something, you have a usability problem.
And the whole trailer shows of an Anti-Gravi? At what point does that show up? Is there a story? Why am I moving this guy around these ridiculous trap-laden areas.
Thankfully I got this with a bundle of other games. But I wouldn't recommend spending any time on it even if it were free.