Brawl Yard
Brawl Yard is a 2-player arena in Pikmin 2, and as its name suggests, it is a yard setting, similar to the second sublevel in Snagret Hole. An overturned bucket is in the middle of the area, which can be used as shelter from the Decorated Cannon Beetles. Other enemies: Cloaking Burrow-nits, Skitter Leaves, Shearwigs and possibly a few Sheargrubs.
Enimies
Decorated Cannon Beetle, Cloaking Burrow-nit, Skitter Leaf, Shearwig and Sheargrub.
Border glitch
There is also an interesting, albeit abusable glitch involved that allows Olimar and Louie to leave the border. The player should throw the Pikmin over the barrier, then walk to a Decorated Cannon Beetle that is near the wall. He/she should attack it, and when it buckles, walk in front of it; it might just throw a leader over the level boundary. This makes it possible to take the opponent's marble from behind. However, a second, invisible barrier will hinder the player from distancing too much from the yard.