I was a bit skeptical of this game when I first got it, but am enjoying it immensely. It's got a ton of variety while remaining quite easy to pick up and play for someone of all ages. In it, you create monsters to go fight other monsters. It sounds a bit repetitive, but the minigames that let you create brand new monster parts are pretty fun and challenging. Then, the reward comes with making your own new monster with your parts! It's a very enjoyable game!
Monster Lab is a unique sort of RPG in which you gather ingredients as loot from battles, use those ingredients to make parts (via Wii motion based minigames), and then assemble those parts into monsters. It's a refreshing change from the usual "leveling up" system, and is a very nice idea. Likewise, the combat system offers something unique. Each part has an element, its own hp, and 2 built-in moves that target specific parts on the enemy monster or even allow you to block, thereby damaging enemy parts. (It's a battle system a little bit reminiscent of the Front Mission games, but set up as a turn-based RPG.) The game has significant drawbacks, but it's definitely worth a rent.
-Interesting alchemy-based leveling system
-Combat system that's simple but offers a good bit of strategy
-Pretty fun visually to see your parts put together into a monster. Offers a bit of artistry, almost like Spore.
-Somewhat poor system of menus and displays. The information you need can be tedious and time-consuming (or even downright impossible) to access
-Too many loading screens and repetitive instruction screens. Sometimes you can spend more time loading and watching intros and info screens than you do actually doing things, especially when it comes to combat
-Story is painfully simple and pretty much nonexistent.
-Cutscenes have very poor sound quality and are not subtitled. I found it nearly impossible to hear any of the dialogue in the cutscenes
-A lot of things in the game get very repetitive. The game makers skimped way too much on variety. It was fun for the first couple of hours, but started to drag near the end.
-Some game objectives are vague or poorly explained. I had to consult a walkthrough a couple of times just to understand what I was supposed to be doing.