Each arena is subtly different, with multiple configurations
of breakable blocks, impassable squares, walls and other obstacles that the two players can use to their advantage to win the match.
You can stack enemies on top
of each other to make mountains
of enemies; you can also add wings to some enemies to let them fly, float, or bounce, or you can make them extra big by giving them a mushroom; you can put enemies or powerups in pipes so that they respawn whenever they get killed / disappear, put them in
breakable blocks / coin boxes to give players a surprise, or combine certain objects and enemies together for all new challenges.