When you have friends over or you just want to play with other people, there's a mode called Arcade Custom. This mode allows you to make your own multiplayer games. You can control the amount of Al Bots on the field, the weapons that can be used, the Maps you play in, and even the types of game you are going to play. This mode can be used for 1-4 players.
A Deathmatch, but your height reflects your rank in the game. The person with the most kills is the tallest (their normal height), whilst the person with the fewest kills is the smallest.
Only the gladiator can score. The person who kills the gladiator becomes the new gladiator. If a non-gladiator kills another non-gladiator, no points/kills are awarded.