Insanely Twisted Shadow Planet is, artistically, an excellent game with decent, gameplay, primarily puzzle based with a spot of action. It's as if Tim Burton directed Asteroids. Overall, there isn't much objectionable content, a spot of violence, though it's rather low in impact, more like Asteroids or Galaga than anything else.
The game is, however, lacking in content, and while the story is simple, it seems too simple.
Also, there was one minigame that involves guiding a rocket through a maze. It can be a bit... Frustrating.
Overall, though, the game is pretty decent, though it's probably worth trying before buying.