Capture the Flag; both sides fight for the flag in the middle and bring it back to their base.
Base defense: attack a base with turrets and other fixed defenses. Attacking team to destroy headquarters. They get dropship reinforcements/respawns. Defending side has heavy base defenses, but no respawns. Shortish timer to force action, and to provide defending side with a time limit before they're 'safe'.
Multi-team death match. Instead of 2 8 man teams, have 4 4 man teams. Chaos and hilarity to ensue.
1 on 1 arena mode.
Horde mode: One side outnumbers the other side... but the smaller side gets infinite respawns. Game is played by swapping sides once the larger non respawning side gets wiped out. Winner is determined by timer. Hmmm... not sure how to handle the swap over maybe swap 3 times, so that all players have a chance on the horde side.
Edited by Zaptruder, 19 February 2013 - 09:23 AM.