Hey, gang, it's been pointed out to me that Guns of Icarus Online is on sale at the moment on Steam at $7.49 for a 4-pack of the collector's edition of the game.

It apparently supports up to 16 players per match, so it could be a suitable game for an upcoming livestream.

That sale ends in about 22 hours (as of this writing).

Garry's Mod is also on sale (75% off), and also supports multiplayer as well. That sale ends Friday.

I have no experience with either game, but they both seem interesting/fun to say the least.