Well, it's a puzzle-adventure game as you've probably read in the reviews. I'd say more of a puzzle game because it doesn't have much of a story. It's a series of puzzles split into levels with a few puzzles in each one. If you're a fan of old school point and click adventures, you'll like it, as it's pretty similar to those.
Puzzle difficulty ranges from easy to very hard. There are puzzles you'll solve at the first try and others that'll leave you scratching your head. The majority of them involve the Wii remote and motion controls in very clever and innovative ways. I don't want to spoil the fun for you, but in each level you'll use the remote differently. There's also a hint system which lowers your score, if used and a ticket system which allows you to continue from the point before you died. You can ignore both, if you want the highest score at the end of each level, but if you lose, you have to start from the beginning of the level. There's also a pretty mediocre rhythm mini-game, which is completely optional. You shake the remote in tune with some classic Capcom tunes and it's not very accurate. Still, it's a fun distraction.
So, there you have it. It's a good game, but not for everyone.