
Solaris
Discover a space strategy game filled with conquest, betrayal and subterfuge. Build alliances, make enemies and fight your way to victory and galactic domination. Will you conquer the galaxy?
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。

Discover a space strategy game filled with conquest, betrayal and subterfuge. Build alliances, make enemies and fight your way to victory and galactic domination. Will you conquer the galaxy?

From the folks behind the BIT.TRIP series comes the frantic insanity that is WOAH DAVE! Help our hero, Dave Lonuts, survive an insane alien invasion and line his pockets with shiny pennies. Hurl alien eggs, skull bombs, and explosive WOAH blocks to stay alive and sky rocket yourself to high score fame and fortune. The brave players who manage to survive the alien onslaught and collect the most coins will be rewarded with top placement on the fierce online leaderboards. Do you have what it takes to be the world’s best Dave? Or will you end up playing second fiddle to another, more powerful Dave?

過去に苛まれる吸血鬼ハンター、ヴィクトリアと、始まったばかりの悪夢に囚われた若い女性、エレノア。二人は力を合わせ、異形の怪物、隠された罠、そして自分たちが思う以上に二人を知り尽くしているかのような存在に立ち向かわなければならない。

ONE MORE LINE is a highly addictive, one button, space disco, skill timing game! Steam edition features 2-4 player local multi-player and no advertising. All for a very low price! Can you put a price on fun though?

You thought you were the only rock climbing hipster around, but these mountains are full of them. Eliminate all competition and claim your rock! Climb, an online multiplayer brawler with short and action packet game sessions!

Join millions of players online in the No.1 Cross Platform pool game! Experience stunning visuals, realistic physics, and fast-paced modes like 8-Ball, 9-Ball, and Blitz. Challenge friends, master trick shots, and climb the leaderboards - new to Steam!

本作は演奏シミュレーションと学園ADVを組み合わせた音楽学園シミュレーターです。 コンコルディア音楽学園のカホンクラブに入部した初日に直面する廃部の危機を回避するために奔走する中で、アンサンブルパートナーと出会うことになります。 ストーリーモードとフリープレイモードのほかに、パートナーとの会話を通じて互いへの理解を深めながら音楽知識を学べます。また、ゲームセンターでのリズムゲーム、プレゼント交換や音楽に関する読み物も楽しめます。最大4人でのアンサンブル演奏では、それぞれが異なるパート、異なる譜面を担当する本格的な合奏が楽しめます!

Golf for Workgroups is a competently designed golf course, ball, player and cart simulation with a swing component designed to be satisfying. Up to four players each navigate a biped around a height field texture mapped to look like a golf hole.

Epic Card Game is a fast-paced card game of fantasy combat designed by Hall of Fame Magic players Rob Dougherty and Darwin Kastle. It has all the amazing game play and beautiful art of a digital trading card game, without the costs: you get unlimited copies of every card!

Fatal Core is a 100% free, community-driven Trading Card Game. Assume the role of one of 6 Lead Characters and battle in a dystopian future full of strange magic and alien technology! Fatal Core features many unusual mechanics, including simultaneous play, open hands, player market, and more.

僕達はドラゴンから逃げ切れた。仲間たちが苦しんでいることに耐えられず、みんなを救い出すために再び危険なダンジョンへ向かうと決めた。暗い暗いダンジョンの中で、僕達は力を合わせてダンジョンの中のドラゴンを退治し、仲間を救出しなければならない。 二人で協力するチームプレイ式ゲーム。 プレイヤーふたりの距離が離れすぎるとHPの損失となり、可視度も落ちてくる。逆に近くなると回復できる。ダッシュ時のプレイヤーふたりは破壊能力のあるラインを生成し、モンスターを殺すやクリスタルの破壊ができる。プレイヤーは互いのポジションを注意し、距離を離して攻撃するか、もしくは距離を縮めてHPを回復するなどができる。

夢のベーカリーカフェを焼いて、作って、育てよう!おいしいペストリーを作り、空間をデザインし、お客さんにサービスを提供しよう。ソロプレイやオンライン協力プレイで友達と一緒にビジネスを拡大し、賑やかなカフェを経営する興奮を味わおう!

In this deeply strategic, full-information battle card game, choose your fighter from a diverse roster of spell-slinging duelists, tag-teaming werewolves, time-traveling boxers, dimensional knights, and more! Each fighter brings their own unique sub-system to combat, and comes with their own complete kit–no deck building or collecting necessary!

Gurgamoth is a flying fighting game where the level is your weapon. Each match is lightning quick and focuses on intense flying combat and getting in your opponent's head. The controls are simple, but the mechanics and interesting levels bring out the game’s depth.

A turn-based rally through Europe with the goal of becoming the richest!

Dragonpath is a top-down hack'n'slash RPG with abilities tied to equipment rather than classes. Carve a bloody path through a broken underground realm inhabited by vicious monsters and few struggling remnants of civilization. Experiment with equipment to find the combination that suits your playstyle best!

a two-player platform-fighter splattered with neon, kinetic movement, and just a sprinkle of bullet time.

君はいつも腹を空かせた若いホバーバイクライダーだ。なんとしても地球が「バクハツ」してしまう前に脱出しなくちゃならねえ。賞金を稼いで、レースに挑んで、とにかくやれることは何でもして火星に行き、Grand Prix で優勝するんだ。

Easy game for easy life. Enjoy.

1つの拠点空港から、自分だけの航空会社を築き上げよう。路線を開設し、運賃とサービス戦略を練り、運航スケジュール、人材、機材、評判などを管理。地域航空会社を世界規模の航空ネットワークへと成長させよう。

Explore the deepest caves with a cup of tea in your hand, reach the heart of the jungle with your finger on a globe, send your highly educated employees to uncivilized tribes and don't let them convince you it's a certain death! The worst case scenario? You will hire new ones.

HoverRace is a racing video game created by GrokkSoft in 1996.

Fast-paced racing game in a retro 80's neon style.

1人から最大6人までで、怪物だらけの街を駆け抜け、生存者にピザを届けろ──すべては謎の霧が始まりだった。

HaberDashers is a console-style arcade (kart) racer for the PC in which players control miniature humanoid inhabitants of an everyday home, racing past outsized household items and through rooms as they compete against human and AI opponents with both driving skills and item pick-ups.

ACT IT OUT XL! is the multiplayer party game created to complete your games night! Get your friends or Twitch viewers to guess your favourite films, songs and video games as you describe, act, draw or sing them!

A fantasy strategy game that combines collectible card and board game mechanics. Build custom decks, choose powerful heroes, and engage in tactical, turn-based battles in competitive PvP leagues and battlefield tournaments.

Big E’s back in action! Working the farm over Summer is never easy - but everyone knows you’re the best. Do your utmost to keep the product moving, the customers happy and the law at bay, and everything’ll turn out great!

Eyes of Hellfire is a co-op gothic horror game inspired by tabletop games, but with a twist - the insidious Host can manipulate your sense of reality

Streets Ablaze is a 3D side-scrolling beat em' up inspired by the arcade and console games we played growing up.

Ironclad Tactics is a fast-paced, card-based tactics game set in an alternate history Civil War - with steam-powered military robots!

Get ready to ragdoll in RagBrawl! Compete as a floppy Tuffling toy with up to 12 players online and show them your stuff in this chaotic party game!

メカズーは、シングルプレイまたは協力プレイで、動力学的に多様な動物を主人公として冒険・攻略する鮮やかな完全3Dワールドを備えている2Dプラットフォームです。古典的なプラットフォームからインスピレーションを得ており、メカズーは新しく創造的、ユニークかつ楽しいゲームプレイ体験を追及するために、コアとなる古典的要素を利用しています。5種の多様な主人公たちは、それぞれユニークな能力を備えています。

オンラインでもオフラインでも遊べる、驚くほどシンプルなポストアポカリプススタイルカードゲームです!

The Chess Themed Chess offers a relaxing, minimalist chess experience with multiple boards, piece sets, AI opponents, and multiplayer. Play in 3D or 2D, learn the game’s history, and explore RPG-themed DLC. Free to Play – Download now and enjoy endless strategy!

Light Bearers 2 is a fast paced hide and seek, asymmetrical multiplayer horror game. A Shadow is trying to corrupt all Light Bears. The Light Bears must use their movement and cunning. To keep each other from becoming corrupted by darkness.