Klonoa has seen releases on Playstation 1 & 2 as well as the GBA. However, since the Wonderswan was never released outside of Japan, not many people are aware of Klonoa: Moonlight Museum. The first great thing to know is that this game is playable without knowing any Japanese. Although you may have a hard time following the story.
Gameplay This game plays much like the GBA version. You are Klonoa and it is your job to restore stolen paintings. To do this you must gather gems as well as keys to open locked doors and star pieces to advance to the next level. Gameplay is simple, collect those items by running on a side-scrolling plane where you can revisit any part of the level you are on to complete the level. Aside from jumping and double-jumping, Klonoa can use the various creatures in the level to attack other animals and hit switches. Klonoa: Moonlight Museum even takes advantage of the Wonderswan's ability to play vertically. The game is also chuck full of puzzles, challenging puzzles. Sometimes frustrating but when you finally figure them out its worth it.
Graphics Graphics, for the Wonderswan, are sharp. The game is in black and white so there isn't a whole lot to say about them. There isn't a lot of detail, the backgrounds are pretty bland but you won't really notice it. Klonoa and his enemies look good; Klonoa having the most detail. The cutscenes inbetween gameplay is done with still shots of the characters that are nicely done in black and white.
Sound Since the cutscenes are just pictures and no one talks, the only real sound is a few sound effects and the background music during the levels.
Replay Value Once you beat the initial game you can go back and play the unlocked EX levels that include tougher challenges. Also, if you manage to not get all the pictures pieces in a certain level, you can also go back to get them.
Klonoa: Moonlight Museum is a solid platformer for the Wonderswan. Challenging puzzles and added EX levels make this a great platformer. Plus its playable without knowing any Japanese so this game is highly recommended.