The mode is started by pressing the big button at spawn, after 30 seconds the enemies will spawn.

After pressing this all augmentation canisters and medbots / repair bots will disappear, so use them if you have to.
Limited weapon mods are available from the start, with more spawning on enemies that can be looted.

The enemies are the common enemies that spawn each wave. New enemies can spawn every 5 waves, starting from wave 6. It is randomly decided which spawn out of the ones that are allowed to spawn that wave, excluding the special waves.
The amount of enemies that are allowed to spawn per wave is limited to 8 up to wave 61, upon which it is increased to 12. An exception being wave 26, which is up to 11.
The amount of enemies that can spawn is the wave number divided by four.

The attack helicopter and doberman enemies only spawn when playing on the cathedral level. Attack helicopters are weak to attacks from the top and bottom, or just regular bullets. Try to throw a grenade onto their blades or use plasma (in normal gameplay mode) or explosives from below in order to destroy them. A hit with a LAW will instantly destroy them.

Helicopters currently only spawn on the cathedral level at wave 70+.

During these waves the normal rules for which enemies will be spawned are ignored and are overwrote with these enemies instead.
For wave 26, the luminous path members are limited to melee weapons only, excluding Gordon Quick, due to this their spawn limit is increased to 11.
These enemies do not have special stats and act as regular enemies.

Boss waves are every 10 waves. Alarms will flash around the level to signal the start of this wave. Enemies will continually respawn while the boss is in play. The boss will need to be defeated in order to progress, when the boss is defeated a 2 minute break will be awarded. During this break all robots are destroyed, all enemies are knocked out, ammo crates, medkits, biocells, upgrade canisters, and zyme will spawn in the starting location.
After the break is over all loose bodies and items will despawn.

Enemies that aren't animals, commandos or robots get randomized ranged weapons. As some of these enemies don't have animations for heavier weapons (i.e. all females, larger males such as Joe Greene and taller ones such as Chad) they have a different set of weapons to use.
Luminous Path members are restricted from these weapons.

Standard troops:

Others:

All enemies get a random melee weapon, as long as they are not an animal, robot, or commando.

All enemies except animals and robots are able to get bonus items, additional items become available with time. Commandos are not allowed pepper guns.

Cloak:

At higher waves enemies have a chance to be cloaked:


At wave 600+ the AI gain the ability to teleport next to you if you can't see them or where they teleport to.

• All enemies spawn across the bridge, the bridge is their only access point.
  
• There are items and ammo hidden around the level that can be used.
  
• The security console can be unlocked at master level, giving access to turrets and Jock.
  
• Helicopters spawn after wave 70, which fly in from across the bridge.

• Enemies spawn from the front and the side elevators.
  
• Small enemies spawn in the side vents.
  
• Bosses spawn on the large elevator every 10 rounds.
  
• Halon gas emitters are at each side and can blind the enemy or extinguish you.
  
• The three security consoles can be accessed with each level invested into computers.
  
• The first console allows you to block off the communications area with electricity.
  
• The second console gives access to two turrets.
  
• The third console allows you to activate two military bots to defend you.