Online Co-Op games on Steam

How Steam games tagged Online Co-Op did, which ones found an audience, and where the gaps are.

The best-known Online Co-Op games

• Counter-Strike 2 (2012): 9,944,999 reviews
• Dota 2 (2013): 2,804,255 reviews
• PUBG: BATTLEGROUNDS (2017): 2,748,724 reviews
• Tom Clancy's Rainbow Six Siege (2015): 1,566,180 reviews
• Team Fortress 2 (2007): 1,255,553 reviews
• Terraria (2011): 1,247,762 reviews
• Rust (2018): 1,176,635 reviews
• HELLDIVERS™ 2 (2024): 847,777 reviews
• ELDEN RING (2022): 834,397 reviews
• Left 4 Dead 2 (2009): 822,865 reviews
• Baldur's Gate 3 (2023): 759,332 reviews
• Dead by Daylight (2016): 690,196 reviews
• Phasmophobia (2020): 685,968 reviews
• Warframe (2013): 681,040 reviews
• Among Us (2018): 662,348 reviews
• Valheim (2021): 475,046 reviews
• Fall Guys (2020): 467,924 reviews
• PAYDAY 2 (2013): 445,882 reviews
• Rocket League® (2015): 431,786 reviews
• Overwatch® (2023): 428,899 reviews
• Call of Duty® (2022): 419,075 reviews
• Palworld (2024): 416,659 reviews
• Brawlhalla (2017): 414,786 reviews
• Lethal Company (2023): 411,978 reviews