I really enjoy this game because it’s quite frankly not too hard for my kids, but has enough challenges for me to not be completely bored while playing with them. My kids are 5 and 6 years old and although they are pretty good at platformers this is still a hard balance to achieve.
This game is really colorful which helps keep the kids attention. The music is fun and it has really simple controls for doing really fantastic looking moves that are generally useful and not just for flash (although the super copy abilities are pretty flashy). Being a four player game we don’t have to take turns which makes it a hell of a lot more fun.
There are some annoying things about this game. If the other players get to far away from player one then they get sucked back to them which can be useful at times, but is really annoying at other times. The biggest flaw I’ve seen is that when player one dies you have to restart the area of the stage which wouldn’t be all bad, but since you also share lives, if the other players use up all your lives you have the start the stage over completely. This is off-set by the other players effectively having unlimited lives after you have no extra guys remaining. Once again sometimes that’s useful, but most of the time it is kind of annoying.
If you have younger kids I would recommend this game, but if you’re kids are older then you might want to pick up something like New Super Mario Bros. Wii or Rayman Origins.