Should've written this review two months ago or something but anyway...
For those few who haven't played any previous Wario Ware game, the series is about a sequence of "microgames", minigames that take 5-10 seconds and usually just one action to complete. You have to solve these in rapid succession (and the pace gets faster as you go along) until you run out of lives. You lose one life every time you fail to archieve the goal of a minigame and gain one whenever you successfully complete the boss game (a minigame without time limit), you start with the maximum of four lives. Instead of levels there are characters, each one has his or her own set of minigames and (long winded) intro and outro. You defeat a character by completing his or her boss stage once. After you have defeated them winning the boss game merely makes the minigames harder (on Level 1, that is, before you defeat the boss once, you have to try to lose those games) and gains you an extra life if you have less than four lives left.
The minigames consist of simple tasks like drawing a line between two points, blowing away enemies or moving some object into position. Your weapons are the stylus and the microphone, the latter used only for blowing into it (and almost all minigames involving it only consist of blowing at the right times). Since almost all characters have some theme going for them that consists of an action that all minigames use (e.g. rubbing, rotating, drawing) there might be a feeling of similarity among them, especially when you play against Mike, whose theme is "blowing into the microphone" (sounds fun, eh?). Generally the variety of graphical styles and the meaning of those actions (rotating can mean inputting a safe combination or navigating a labyrinth) manages to remove the feeling of similarity, except for Mike's games.
If you manage to beat a certain score for a character you get a bonus... uh... thing. Those range from an egg timer or yoyo to longer minigames you play for the highscore (these come with their own bonuses for beating a certain score). Except for the minigames these are completely useless and you'll throw them into your storage room (you can store them on the character field or the storage room) after five seconds and never dig them up again.
The game is really short and easy, you'll beat all characters and unlock (almost) all bonuses in two hours max. After that you can only try to beat your highscores. There is also a mode that lets you play one minigame over and over again to see how many times you can complete it and if you get a certain score at all of them you'll get another bonus (I haven't got that but I extrapolate that from the first WW game, where you got one for that as well). The game is really fun at first but the lack of purpose will soon take its toll on your fun.
Worth mentioning is the issue with the microphone and loud areas: The engine of a car apparently sounds the same as someone blowing into the mic so if you're playing WW:T on a trip you might want to stay clear of the mic games since constant blowing will not win ALL of them. That's bad for a handheld game you'll most likely play on a car trip.
Graphics: Well suited but not impressive, 0 (good/par)
Sound: some of the music is a bit repetitive and nerve grinding after a while but it doens't matter much. 0 (good/par)
Controls: Can't get any easier. Using the stylus is intuitive though blowing into the mic might be a bit embarrassing in public. + (great)
Final verdict (aka Fun): 0 (good/par). A good game but gets boring way too fast. Fun while it lasts, though.