
It Takes Two
フレンドパスで1人購入すれば最後まで2人で遊べるGOTY受賞の2人専用名作。
みんなで失敗なく盛り上がれる定番人気作(940本)から、知る人ぞ知る隠れた名作(517本)までまとめました。
一覧にまだ載っていない協力・パーティーゲームも、Steamストアからリアルタイムで一緒に探せます。

フレンドパスで1人購入すれば最後まで2人で遊べるGOTY受賞の2人専用名作。

1人が購入すればフレンドは無料招待。異なる機種でも遊べる2人専用協力作。

Unleash the apex worm in you! Join a world where you eat to grow and aim to become the largest worm around. Dodge viruses, cut off enemy paths, and indulge in addictive multiplayer action. Custom skins, game modes, and more await!

A fun hidden role game where you backstab your co-workers and get mad at your co-workers for backstabbing you. (6-10 players)

Battle friends over air, land and sea in this epic WW2-themed battle strategy game.

Enjoy some of the best loved Flash games of the past in this awesome time capsule of over 60 Ninja Kiwi classics. Experience a piece of history and play the original Flash games that spawned the worldwide phenomenon of Bloons TD.

Behold, the miracle of life… packed into cubes! Create fantastic creatures in an open-world sandbox game like no other. Explore, craft, and survive—all with the help of your very own creations.

An online game that you'll play with 3-11 players as a Prisoner or a Guard and will try to escape or prevent escapes. Loot, Craft, and make your way to the exit, or investigate and arrest wanted players as a guard!

Take a 5 minute break to de-stress with this high-intensity, ultra simple, retro arcade shooter! Take down airplanes. Dig tunnels. Hide and seek shelter. Try and beat the highscore. That's all. Afterwards, you will go back to your life with renewed energy of body and mind.

Castle of Blackwaterは、魔法のひねりを加えた2Dのアクション満載のソーシャルディダクションゲームです。この信頼と裏切りの激しいゲームでは、最大10人の見知らぬ人々が危険と欺瞞の城に閉じ込められ、任務を完了し命をかけて脱出することを目指します。

Transform your virtual tabletop RPG experience in Game Master Engine’s lush 3D multiplayer RPG simulator. Whether you're a seasoned game master or just starting out, GME makes it easy to explore, create, and run custom games, all while bringing your players together for unforgettable adventures.

A free-to-play Single-and-Multiplayer social deduction game in which role-based play rewards those who rely on strategy and their creative instincts. Also features full cross-play, cross-progression, and a story-rich experience. Supports up to 8 players with any combination of humans and AI.

ストラテジー... 魔女... そしてタイムトラベル!シングルプレイヤーとCo-opキャンペーンの両方を特徴とし、小規模なインディーチームによってデザインされたTimeMeltersは、プレイヤーが自分自身と共に過去に戻り、戦うことができるユニークなゲームメカニックを備えた挑戦的なストラテジーアドベンチャーゲームです。

a classic arcade shooter game. You can play with up to 4 people locally, or using Steam Remote play.

The original, uncompleted version of Vectorio. Claim resources, unlock new buildings, and expand your defenses as you fight back against enemy forces in the classic edition of Vectorio! Play for free now.

2-4 Sneaky and squeaky low-poly mice face off against a lone cat in the battlefield of a human house. Mice use proximity chat to communicate with other players, while the cat hunts their noises. Will the mice perform enough tasks to destroy the house, or will the cat defeat enough mice to save it?

Dummy Falls is a co-op game where you and your teammate tries to overcome various obstacles until the end.

Goi: Spooky Run is 3-10 players “Catch me if you can” online party survival game. Put your friendship to the test! Prank your friends, survive the ghost hunt, and be the last one standing in this chaos!

Crashed on a strange island, survivors must forage, craft, and complete objectives to stay alive. But ferocious beasts, harsh weather, and secret saboteurs seek to make sure they never escape. Betray your friends or survive the island in Betrayal Beach, a 4-8 player social deduction survival game.

Built from the ground up, Rock Life is the next generation of immersion and simulations. Live, do, and experience what it is like to truly become one with nature... as a rock!

これはゲーム「Ale & Tale Tavern」の無料版です。オープンワールド、アクション、釣り、狩り、探検、楽しさ、多彩なクエストなど、様々なジャンルを組み合わせて、このゲームを作り出した!そしてもちろん、調理!ソロでも友達とでも体験して、世界中に食事を提供しよう!

Team up with friends and dive into adventure! Rescue dwellers, let them work for you so they farm resources and protect you from enemies. Upgrade your equipment, explore new lands, complete quests and fight evil with glory!

Free multiplayer 2D ghost hunting game that you can play with friends created by a small game dev team.

You're now a monkey*, the room is full of stuff*, collect the stuff in the cardboard box while running away from the possessed monkey. EASY! Don't get caught! And if you're the one possessed, catch every monkey and explode them into the Bananaverse*.

CS2D is a free fast-paced top-down multiplayer shooter. Featuring many different game modes, a built-in map editor and much more.

Fetch some friends for fun, fast online multiplayer. One of you is the baddie! Everybody else is trying to find the baddie. The baddie is invisible. At least, most of the time...

Inspired by the party games Werewolf and The Resistance, MINDNIGHT is a cyberpunk online social deduction game of deceit, accusations and unpredictability. It challenges your ability to lie and detect others that are trying to be deceptive.

The genre defining VR model train game. Build and ride the model train layout of your dreams without the cost and excessive model foam dust getting in your nose!

国家の終焉は、現代文明の崩壊までのローマの台頭をカバーする4x ターンベースの壮大な戦略ウォーゲームです。

Darkness is coming. How long can YOU survive? Build your base by day, defend it by night. Play in online or local co-op. Stay alive as long as you can.

Pyroworks is a free-to-play online multiplayer game containing fireworks from real-life companies from all over the globe. You can choose to make your own show, cause destruction and chaos or simulate new years. Don't miss out on playing with your friends - the most fun part.

Throbax TD is the "Tower Defense" game you are looking for: Help Ughlar fight his way through 50 levels, buy over 100 upgrades and get all of the 50+ achievements.

A short sandbox rpg game that takes place on a square planet. Explore the world, gather resources, build a home and become stronger.

リラックス感あふれる都市建設ゲームで、町を賑やかな大都市に成長させましょう。自分のペースで物品を製造し、交通システムを管理し、有名ランドマークを建てることができます。

Blip is a platform where players and creators come together to build, play, and share unique gaming experiences. An open-source alternative to Roblox.

Build your café, brew perfect coffee, and sabotage your rivals in this chaotic multiplayer café simulator. Start small… and learn how far you’re willing to go.