Really nice gamefeel! The movement was smooth, and while it was a bit hard to control the gravity well with keyboard, it wasn't terrible and I could definitely see it working better with an actual gamepad. Felt like some kind of awesome space-telekinesis user. :D To improve it, I think I'd suggest focusing a bit on making it aesthetically consistent and thematic (right now the polygons somewhat conflict with the gravity well and other effects).
Overall, really nice job!