This is a well-polished game, the visual style is good-looking and consistent. At fist I was not sure what to do, why I can't shift and what shifting means, but after I got the hold of the gameplay, it really sucked me in. The audiovisal effects of shifting and the fact that I can just go through anything (except black holes of course) felt amazing.
The only issue I had was that using space and shift at the same time (or at least on quick succession) was a bit finger-twisting for me. Also it takes a lot of practice to switch from the jumpy kind of control to the shifty, arrow-like control.
Overall, a great and fun experience, will come back for more.