Co-Optimus - Steam Co-Op Game Matchmaking *BETA*

Steam Co-Op Games in Common

Spyker

	Left 4 Dead 2 Take the role of a different set of survivors as you use all new blunt force weapons, chainsaws and new guns in the sequel to Left 4 Dead. Teamwork is even more crucial as high intensity moments require greater communication to survive.To enable split screen refer to this post.
	Civilization V Research is shared between players when choosing to play on the same team. If both players research the same item, the time it takes is reduced. When one player discovered a technology, the other gets it as well.Players share the benefits of landmarks, ruins, and other discoveries on the map.Players share the map. Diplomatic options are available as well to trade resources, gold, and units.Co-Op is played in multiplayer with each player picking to join the same "team." It's assumed a balance of 3 players vs 3 AI are chosen, but you can weight it to 3vs1vs1vs1 or 3vs2 or 2vs1, etc.
	Audiosurf Audiosurf includes the "Double Vision" character, which places two cars on a four-track-wide course. Both players are on the same screen.Control is mouse for one player and keyboard for the other, or using one stick each on the same Xbox 360 Controller.
	Beat Hazard Team up with a friend and groove out/shoot down foes to your favorite tracks. Beat Hazard Ultra DLC is required.
	Portal 2 Portal 2 will have a co-op campaign. Players take control of a robot and work through puzzles that require two players to work together to solve.
	Capsized Play through the entire campaign and challenge modes with a friend as you make your way off of a harsh alien world.
	Atom Zombie Smasher Up to three players can play at the same time - each controlling their own cursor to select actions like fire artillery and trigger dynamite.
	Serious Sam Double D XXL Sweet and simple two player local co-op.
	Shank 2 Two players can play locally or online in Shank 2s Survival Mode.
	Serious Sam 3: BFE Team up through the campaign with up to 15 other friends for frantic, old-school shooting action.
	Shank Shank has a 2 player co-op campaign with scenarios and bosses specifically designed for co-op.
	Jamestown Team up with up to four players who can choose various ships to power up.
	Serious Sam 2 Go to war against Mental’s horde with up to 6 players online or 4 players in local splitscreen and annihilate everything that moves across 45 levels of mayhem.
	Insanely Twisted Shadow Planet Team up with friends through the game's co-op "Lantern Run" mode which involves a tactical approach to lighting and surviving.
	Awesomenauts Three players can team up locally or online and play against bots.
	Shatter Play co-op in Time Attack and Endless modes. Gameplay is a bit like Pong meets Arkanoid, each player controls their own ship/paddle.
	Dungeon Defenders Team up as one of four characters each with their own unique abilities and traps to conquer dungeons in this tower defense action/RPG hybrid.
	Trine 2: Complete Story A side-scrolling puzzle-platforming game featuring up to three players working together to complete the campaign. Three player couch co-op, online co-op, and combo co-op (i.e., a mix of couch and online co-op) is supported throughout the campaign. Each player controls one of the three heroes.
	No Time To Explain Remastered Two players grab guns 'n stuff and head out on a shooty adventure.
	Monaco: What's Yours is Mine Team up with up to four people on the same screen or online to steal everything that isn't nailed down
	Sacred Citadel Up to three players can join forces in local or online co-op throughout the entire campaign.
	Hammerwatch Solo or cooperate in this adventure from bottom to top of Castle Hammerwatch. Kill hordes of enemies with varied looks and features through four unique enviroments with traps, hidden secrets and puzzles.
	Risk of Rain Team up with 4 friends to fight your way off an alien planet with up to 12 playable characters, randomized levels, and a difficulty level that increases the longer you play
	Spelunky Four players can explore the world of Spelunky together in local co-op play. The Spelunky SD mod allows for online co-op play, too!
	Lovers in a Dangerous Spacetime Players run around the ship controlling turrets, shields, lasers, and steering.
	Rocket League You and some friends can team up against the AI in 2v2, 3v3, or 4v4 matches, either online or split screen.
	Viscera Cleanup Detail: Shadow Warrior You can enlist some friends/coworkers to come and help you clean up (or make even more mess).
	Magicka Four player co-op is available in all game modes and types including a story mode and an unlockable survival mode. While you can't drop in to a game, you can drop out and not break the session if you aren't the host.
	Octodad: Dadliest Catch Up to four players team up to control Octodad's crazy flailing tentacle-limbs.
	Project Zomboid Players can team up and survive together in an open world persistent server.
	Keep Talking and Nobody Explodes One player is responsible for defusing the bomb and the other players instruct them on what to do using information from the Bomb Defusal Manual. Players just need to be able to communicate with one another, so you don't all have to be in the same room, but it is more fun that way.
	Steredenn: Binary Stars 2 ships, 4 weapons, 1 lifebar - test your friendships!
	Brawlhalla Custom play allows up to four players to test their skills against the AI in various modes.
	Stardew Valley Up to three other players can join the host player as farmhands. Farmhands can do almost anything the main player can do. They can farm, mine, fight, fish, forage, marry NPCs and take part in festivals. Each player has their own inventory. When a farmhand is not connected, their inventory can be managed through a chest in their cabin.
	Spelunky 2 Four players can explore the world of Spelunky 2 together in local or online co-op play
	Vertigo Remastered The game features an asymmetrical coop-mode. While the main player uses VR to play the game, a second non-VR-player can enter as a spectator who has the ability to shoot lasers from the spectator camera.
	Guacamelee! 2 Four player local, drop-in/drop-out co-op is supported in the campaign once the first player reaches a certain part about 15 to 20 minutes into it. Friends can jump in at any time after that to help out! The difficulty of enemies will scale to keep things challenging as players drop in and out.
	Unrailed! Up to four players can team up locally (couch co-op) or online to build tracks and keep the train from derailing