On spawning you are given two weapons, a "freeze rifle" and a "thawsaw". The gameplay mechanic is fun and simple, it is a team based game mode where shooting someone on the opposing team freezes them in place, making them unable to move. You can thaw/unfreeze players on your own team that are frozen by using the thawsaw on them, if all members of one team are frozen at the same time, the other team wins.
This introduces a more interesting gameplay mechanic than simple teamLMS instagib as the option to unfreeze players on your team provides another layer of tactics; for instance players you have frozen can act as bait or a "trap" for other players on the opposing team who might rush in carelessly to unfreeze their teammate while you hide away, shooting them as soon as they get near the frozen player.
The wad itself will contain no maps, only scripts, decorate and other needed lumps for the game mode, which can be loaded with any of your favorite wads that contain mapsets with deathmatch starts.
I also plan to extend this to allow for further possibilities, such as freezetag CTF.
Update: Now with proximity based thawing!
[spoiler]

Old screenshots with old sprites:
[spoiler]

Notice on the right someone has just unfrozen his team mate with a thawsaw.

The more players there are the more fun this is (unless the map is too small).

Don't mind me, just owning those 3 blue team players.[/spoiler]
DOWNLOAD: Get the wad here http://www.[bad site]/wads/, control+F ftagb and choose the wad with the highest number, you need to reset the map once (using map command) for everything to initialize, also you should set sv_noteamswitch to true as team switching mid game can cause the game to crash.
What I need currently, any help MUCH appreciated:
Find a way to track a player's damage to others so as to award individual "frags".
Good looking freeze rifle and thawsaw sprites?