World-altering platformers are almost a dime a dozen these days, but when this game was released it received praise for being quirky and innovative.
Even now it's difficult to argue against that, the game has a habit of pulling a something new and somewhat interesting mechanic out of the hat every time you start feeling like you're getting used to it.
On the other hand, and probably far more important, the game is not fun to play. The growth of mechanics become boring - or even frustrating - sometimes before you've finished seeing them for the first time.
It feels very much like a university game design project, made to demonstrate a combination of physics and creative obstacles. That might be because it is a university game design project. I'm not sure.
The game certainly had a lot of potential to be fun. Indeed for the latter half of the main game I was having fun, wondering what would happen next. But the game commits four cardinal sins each of which could ruin any game.
Firstly, some of the mechanics are almost unplayable. The flint rocks and the spring-reeds are particularly worthy of note as elements that bring a sense of dread every time they appear.
Secondly, the collision detection is unreliable at best. Sometimes you can survive a surprisingly long fall or getting crushed by rocks, at other times you can die from a much smaller rock touching you with barely any movement.
Third, some of the additional challenges and achievements are terribly thought out.
The game has three bonus stages that are on a par with I Wanna Be The Guy for difficulty. There's an achievement for beating those, which makes sense. There are also achievements for beating 5 levels with limited rotations, or in a certain time, or without dying too much. Those make sense too.
What doesn't make sense is the achievement for beating ALL levels - including those unreasonably hard ones - with limited rotations, in a certain time, and without dying too much. And further still, the one for doing all that with the fewest rotations possible, a ridiculously low time and without dying AT ALL.
There are also three speedrun achievements, the latter two of which rely almost entirely on getting lucky with the placement of randomised projectiles. Replaying the same twenty minutes over and over until it works right is not fun.
The last sin the game commits is adding content badly. Following its PC release a Wii version was made, which allowed for dynamic world rotation instead of the 90-degree locked turns in the PC version. The additional bonus levels and challenges were then retrofitted into the PC version, but the smooth rotation was not even though many of them were designed for it. This makes the PC version much harder than it should be for much of the content.
I need to emphasize that finding the challenges unreasonable is not the whining of a bad player. I'd accept such a claim for middling no-death runs in Super Meat Boy, but these so-called challenges are just not viable for anyone. Experienced players unanimously conclude that including the bonus levels within the challenge modes when they were all added was either an oversight or a mistake.