The wackyest and one of the greatest games on the GBA.
Good:
+ A whole variety of microgames
+ Unlocking things is fun
+ Long replay value
+ Multiplayer on one GBA
Bad:
- Can't skip cutscene if first time playing genre
Every microgame belongs to a genre. The microgame can be from picking noses to jumping barrels in Donkey Kong. They each have 3 difficulties. After every 15-20 microgames, you play a boss minigame which can be pretty challenging and it lasts longer than your usual microgame. After that, the difficulty of the microgames go up one level. You will get addicted to this game by trying to unlock everything. There is also multiplayer but it's not the type of multiplayer you expect. You and a friend can actually play each other by using one GBA. One person uses L and the other uses R. It really works and is a blast of fun.
There really is nothing bad about the game except you can't skip the cutscene during the first time. It's not a major problem and some of the cutscenes are pretty entertaining.
Overall: This is one of the most fun games on the GBA and you should at least play one Wario Ware game because if you don't you are missing out of this fantastic experience.