A nice little platformery romp that's neither too hard nor too easy. Or especially original, but it does what it does well enough that I can forgive that.
Something like half the game or so is a super meat boy-esque platforming engine, with wall jumps and decently fast move speed and all that. Unfortunately, the physics here have a few issues; walljumps will randomly fail to activate, and air control is next to non-existent. Clearing the main game and all the challenge levels did not help me understand how momentum in the air works in the slightest; fortunately air control isn't a big factor in the game. The level design here is pretty solid throughout, throwing in a variety of standard platforming elements; crumbling floors/walls, gravity switches, precarious jumping puzzles, all the usual. Again, nothing new, but done well enough that it works. The last string of levels in the main game and about half the challenge levels fall victim to some platforming sins, unfortunately, but aside from them there's a lot to like here.
Another quarter of the game is basically VVVVVV-lite; you play as a young girl who can't jump but can switch between floor and ceiling. The main issue here is that she has literally no weight to her at all and very casually floats up and down with gravity switches; it really feels awkward and not especially well-executed. Fortunately the levels here never get too difficult and this mechanic seems to be axed earlier than the others for some reason. There are some interesting puzzles, but this section also tends to have the issue of the background hiding collectibles.
The last quarter is a runner-style game incorporating more gravity-switching; often accompanied with rather precise jumps and well-placed enemies. The tail-end of these levels also fall victim to long sequences of really tight jumps, and a wind mechanic introduced near the end leads to sudden physics changes that are barely visible on-screen. Other than that these levels are competent enough.
Tying the whole thing together is visuals that remind me most specifically of Knytt Underground and LIMBO; black foreground and characters of the latter and vibrant backgrounds behind dark foreground of the former. The music is a very relaxed soundtrack that helps lessen frustration and is really quite pretty; not that special but it serves its purpose well.
Also there might be a story here, but not really, it's mostly platforming action.
The main game will run you about 3 hours, maybe more if you go for all collectibles/time trials/no death runs. It's not especially long but it's not especially expensive either and I certainly don't regret buying it.