I am not sure this would be fun even if it did work like it was supposed to.
For starters, the controls simply aren't up to snuff here. For one, you need pretty precise lighting and a proper surface for this to work. I had to try several rooms and seats in my house before I found one that worked reliably and even then it only works when the light coming through the windows is just so. This flaw alone is pretty serious, esp. when you consider this system is meant to be portable. Even if you weren't embarrassed by silly you looked--and I'd imagine a lot of children wouldn't be--you couldn't play this on a train or in the back seat of a car. Once a suitable location is found, players are forced to continually recalibrate for each game. Every now and again, after a few rounds, the camera will just refuse to recognize the player which pretty much forces an end of the game (and, naturally, this always seems to happen just as you're finally really getting into it). Long story short, this game is finicky to the point that it barely even works.
To its credit, the mini-games have the classic Warioware humor and are fun while you get to play them but there's altogether too few of them and they never seem to string enough in a row to really draw you in. The addictive aspect of mini-games is that you know you'll lose all the work you've accomplished in the last (infinitely long) thirty seconds if you screw up just one game and that aspect is lost w/ constant stopping and recalibration. Even if this worked one hundred percent of the time, I am just not sure there's really enough here for all but the most casual of gamers.
Not every game has to be some huge involved thing and I like games that show off the unusual capabilities of various systems but Warioware Snapped seems more likely to prove that cameras aren't viable video game controllers than anything. Even as a relatively cheap and quick download from the eStore, this isn't worth the frustration.