Bomberman diehards can rest easy, interested new comers have a great game to start with and the PSP's library now has a solid title that actually makes use of the game-sharing feature. The little man who could - by bombing - has made the transition to PSP very nicely, but has brought his baggage with him: single-player is a stone around a strong Bomberman neck. The good news, the big news, is that the game's fast and addictive multiplayer is mostly intact.
Ignoring the 360's gruesome revision of the franchise, the PSP's Bomberman is the iconic character in classic situations. The 3D look, the PSP's nice wide aspect ratio, and all the showy new stuff you can do with items advance the standards of the series' graphics and gameplay while staying very close to the franchise's roots (and fans' hearts).
The single-player modes of "Normal" and "Classic" sum up to about 150 levels, but not one is as entertaining as five minutes with some friends. Partially because you can gloat when you beat a friend, but partially since the computer is a cunning devil even on lower difficulty levels. Multiplayer is the clear choice for actual fun; proceed past the first few maps of the single player, and the PSP isn't just playing a good game, it's playing a dirty game.
You're much better off playing against friends. The lack of real wireless connectivity and competition is a shame, but game sharing almost makes up for it. Ad-hoc local network play lets you send the game to up to three other players, and all four of you can play on separate PSPs from one UMD. Although the PSP's touchy hardware inflicts a certain looseness on the controls, the heart of frantic and explosive multiplayer is in perfect form here. Being able to actually play with anyone nearby who has a PSP isn't icing on the cake - it is the cake.
Bomberman is still Bomberman; the game won't turn new heads. The graphics are very clean but they aren't going to pull handhelds into the future, and the game is still a very small scale world whose only currency is bombs. This isn't a game trying to reinvent the wheel, but rather one that's just trying to roll along. And if that's what you're looking for, it's a blast.