A single and multiplayer (uncommon, these days) demo for the crazed, doom esq shooter, Painkiller: overdose has recently been released onto FilePlanet.

Two single player levels are included in the demo, a long with pretty much the entire multiplayer component also available for tryout. It contains some original modes, so they are detailed below.

Free-for-All: Standard deathmatch.
Duel: One on one deathmatch
Team Deathmatch: Exactly what it says on the tin.
People Can Fly: Rocket Launcher/Chaingun only, and you can only damage people while they are in the air.
Capture the Flag: Exactly what it says on the tin.
Last Man Standing: Deathmatch but with lives, rather than most-kills-wins.
Voosh: Everyone starts with the same weapons, which all change at certain points, always the same as the other players
The Light Bearer: One powerup available, stays active with user until killed, when it is available again.