Good....For Kids.
Gameplay:
The gamplay is fine with a 3rd person camera angle, there are stealth and puzzle missions as well as just plain action. To put it more simple its just like a mediocre 3-d platformer / adventure game. There is nothing much to it.
Graphics:
Remember Tarzan? An Old PC platformer. The graphics are somewhat similar to that title and if you haven't heard of Tarzan the graphics of Madagascar are okay. You won't find much special effects or half life like water effects but they might please some audiences.
Sound:
You can't go wrong here, the sounds of Madagascar are good. Plus the voice acting is from the original cast members of the animated film. The background musics are pretty decent too. So there is at least one good thing in this title.
Value:
You'll end it in like 8, 9 hours or maybe less and you won't feel like playing it again.
Buy or Rent?
Rent probably, Only recomended to kids.
My final statement would be that Madagascar (both film and game should have been released 7-8 years ago.)