Maybe we should come up with a specific artistic direction when it comes to characters, weapons and levels, considering whether or not they are aliens or humans. For instance, human weaponry and characters tend to be more streamline and have a rustic metal quality while alien weaponry is big, uses undefined materials, and has lots of little lights on them. Humans can have the conventional weaponry like the shotgun, machine gun, and bazooka while the aliens can have the odd weaponry like the nex, electro, and cylink. The characters and arenas could reflect those ideas. It would be cool if people would start a game and quickly identify whether it is an alien or human arena.
I think that this would be a good idea to consider down the road when people are making new stuff for the game, what do you think?