According to Abzug, "We went with a co-op multiplayer mode because we thought it worked better for our game (with) the Nano Forge abilities. We have Nano Forge abilities that give different powers, for example, Impact – the first one you get in the game – that knocks things flying and blows holes in walls. Later on you get other abilities: Shockwave knocks your enemies up in the air and suspends them in stasis for a few seconds; Shell, puts a forcefield around you and blocks all incoming damage.”
“Now picture that in a multiplayer game where you take Shell so you’re the one we all gather around so you can pop it up when we need it. I take Shockwave to act as crowd control for the group," Abzug added, "You take Commando so your weapons do more damage and you take Impact to knock things flying when they get too close. It makes it better to work together as a team.”
Other Volition developers stated earlier in the year that the competitive multiplayer in Red Faction: Guerrilla didn't work as well as they wanted, and it was difficult in balancing human vs. human combat. The 'horde' mode in Armageddon frees up more development time away from having to worry about that factor.