This is a pretty straightforward suggestion for Special rounds in Breach to possibly include in the Special Round vote. They should be simple to setup as well since they only affect what spawns really.
Doom: When facing a demonic invasion, one doomguy was enough. When facing SCPs we may need a few more.
Spawns: 45% MTF Tau 5 - 20% researcher - 35% random SCPs (or demonic type SCPs).
Details: Disable Nuke?
Bomberman: Play a game of bomberman, avoid the bombs released by SCP-2845
Spawns: SCPs spawn 4 SCP-2845, standard round spawns otherwise.
Details: Standard round rules. Alternatively could be d-class only.
Swordfight: Go medieval during a containment breach.
Spawns: 50% scp-076 MTF - 50% scp-076 SCP
Details: Disable gate A, B. Disable Nuke. Disable spawns.