Just when I thought the 2-D side-scrollers were dead.
The soundtrack is good, but not great. I learned where Wario's victory theme in SSBB comes from, to say the least. Other than that, I have nothing to say.
The treasures and missions are a great way to challenge yourself. I can barely do any of the missions, and the treasures are hard to find. Whoever made this game is brilliant.
But my favorite part of the game is the get-to-the-end-then-get-the-hell-out levels! Quite a few different paths open when you're making the return trip. You'll have to do each level at least twice if you want to get everything.
The bosses are expertly designed, the levels are unique, the main character is Wario-ish... It's not flawless, though. It's short in terms of story, and the characters are pathetic save Wario. The ground-pound controls are a teeny bit awkward... actually, that's all I can think of. I recommend this game to any Wario fans out there, I believe it's got everything you're looking for in a Wario game.