#1
I noticed a few more games that are free to play on Steam that might be worth trying out. As such I thought I would collect them all together here for our reference.
Tried Path of Exile - ARPG, akin to Diablo 3 and Torchlight 2
Warframe - A co-op FPS with RPG-like elements and ninja moves.
Neverwinter - An MMO based on D&D 4th edition.
Alien Swarm - 4 player squad-based top-down tactical shooter.
Firefall - A Borderlands-esque FPS MMO.
Not Tried No More Room in Hell - Looks to be a L4D/Killing Floor hybrid.
War Thunder - WWII based war MMO, looks a bit like the Battlefield games.
Tribes: Ascend - An FPS akin to the old Unreal Tournament games.
Planetside 2 - An FPS MMO with large scale battles, vehicles and the like.
Heros and Generals - An FPS MMO based on WWII with online co-op campaign.
Robocraft - Looks to be a mix between Space Engineers / Kerbal Space Program where you make vehicles and fight them.
Enjoy!
If you try out any, let us know what you think!