Bomberman Spar Room...

[maximus_asinus]

There isn't much you can do to a themed level like this. The level has a specific function and it is important not to over complicate and make it too distracting. I would leave the ring itself alone, the walls have tile errors however, the seating outside of the arena is a little haphazard (maybe try long benches), the floor outside the arena is plain, and shrink the level down -- you don't really need all that space around the outside of the arena.