Half-assed in every way, shape, and form, Act Zero simply has no real reason to exist. Too bad it does.
Act Zero holds the dubious honor of being worse.
This new look is apparent once you start the game, and the developers tried to cover this up by making a new storyline. Some forgettable crap about being a test subject and having to escape by making the unfortunate player suffer through 99 repetitive levels of one of the worst games ever made or something like that.
Of course, even if it were the classic, charmingly iconic design of the old Bomberman games, it would still be nearly unplayable because of the horrendous design. You can play over Live against up to 7 players, or suffer through 99 levels in singleplayer mode with one life and no continues. Since there's no way to save and continue later on, you have to blow through all 99 levels in one sitting without dying. This tests your patience much more than your skills.
A new gameplay type of Act Zero is 'first-person bomber mode' which is misleading. Actually it's third-person, but that's irrelevant since the change is crap anyway. Since this is a series so dependent on quick reactions, you're bound to get caught up in a bomb you couldn't see or react to. And the camera doesn't even follow your movements, instead you have to move the camera yourself. To make up for this, the developers issued a health bar so you can actually survive explosions, but now the gameplay is less tense and frantic than what the series is known for. The whole mode is as useless as it sounds. Thankfully, the developers also allow the classic overhead Bomberman style, with one-hit kills like before. There are items that protect you from bombs, but for the most part this is a complete improvement over the useless first-person mode.
You can collect a variety of powerups and items, but there's still less than a dozen of them, making the list feel inferior to even the really old Bomberman games. Even with all that, the multiplayer is still really disappointing. For one, there's no offline multiplayer. Whatsoever. There is online, but the battles are thin on content and feel exactly the same since there are so few items.
It also looks and sounds bad. Outside of some shiny textures, the game looks like a first-generation Xbox game, with ugly environments and character models. Completely horrendous for Xbox 360 standards. There's also a generic song that loops in the background but is completely forgettable. This game is nothing more than a ripoff, even compared to some Xbox Live Arcade games.