Dynabombs are an infinite supply of bombs that the player can drop at any time
he doesn't have anything else to drop. They explode in a cross shaped pattern,
and may have strange results when they kill enemies. (For example, Yam Yams
will only give off the center element of their pattern.)

This pickup allows Dynabomb explosions to destroy brick walls, rather than
stopping at the first wall. Picking up 2 of these will only get you extra
points.