After a whole lot of work, may I present for download Swarm Tactics 0.5 which includes The Darkness 0.5.
No longer is it impossible for player vs player in alien swarm.
The rules are simple. You get 5 points each for player kills till the max is reached for the game mode.
TDM Max = 300 points to win for a team
Tactics Max = 200 points to win for a team
It can be changed to a different value by server or if cheats are set to on as well.
I plan to make it possible to change that later via the menu.
Swarm Tactics 0.5 includes:
Swarm Tactics 2v2v2v2
The Darkness 0.5 includes
Darkness Team Deathmatch
Darkness Tactics 2v2v2v2
3 maps + 2 of my own vmf type maps for you to play with. Those two arent quite finished yet.
Note that you need to select the gamemode within the actual lobby itself, after you select the correct campaign for the gamemode you want.