Its OK so far, but I don't know how much I'll end up liking it.
First, the loading is crazy. It loads the loading screen, then loads a video(!?) then the game. Way too much loading - for me, the UI and general flow of the game is worse than Wipeout and not done well IMO.
The level progression is very linear - I guess you can go back to the level select and choose another of the three sets of steps, but because that takes 10 minutes of loading you don't bother and just take what comes next. And I don't get the impression I'll want to replay any of these levels, which reinforces the potential shortness of the game.
The mercury is a little too gelatinous to me. I thought it would be more liquidy. Plus the levels don't tilt very much - perhaps I've been playing monkey ball too much.
Getting 16% through the game after only doing the tutorial causes some concern, especially as the first level isn't that difficult really.
But overall the feel of the game is pretty nice, and I'm not hating it yet. It fills a nice gap in my collection for a more contemplative game, along with MGA (which I haven't started yet). No Lumines for me (I just don't get the appeal, but i'll borrow it from a friend to give it a go)
I award it a Meh+