Oh wow, this game are so many hours of my life. For some reason I didn't remember it for last years list. Back then as a european I wasn't aware it is actually part of the Bomberman series, I thought it was a Bomberman clone, as it was called Dyna Blaster in europe. Outside of europe it is called Bomberman, again without number, although it is different to the five years earlier released original Bomberman.
The game has a single-player mode with slow slow progression, as in each stage you got only one upgrade and you started with practically nothing. But it worked, as the monsters in each stage got more and more difficult to beat. The different worlds had differing designs and the levels became much much bigger. But the real fun was multiplayer. Normal multiplayer was already hectic and so much fun, but skull.mode brought that up to a new level. Sometimes instead of upgrade skulls were revealed instead of upgrades. And they did stuff to you for a limited time: made you slower, made you faster, inverted controls or something like this. And the best part: you could infect other players with it, by running over them.