Not out of the box — but the Black Mesa: Cooperative mod makes it co-op. Black Mesa is a sci-fi shooter game released in 2020, 95% positive on Steam (127,693 reviews), with 907 playing right now. $19.99 on Steam.
Community co-op build; less polished than Sven Co-op. Steam lists Black Mesa as single-player, so it won't show up in Steam's own "games we both own" view as something you can play together — Ready Up counts it anyway, marked "Via mod", and you can hide mod-only games with one filter if that's not your thing.
Relive Half-Life.
Steam tags: FPS, Remake, Action, Sci-fi, First-Person, Singleplayer, Shooter, Atmospheric
Ready Up compares two Steam libraries and shows every multiplayer game you both have — including whether Black Mesa is one of them — then helps you pick tonight's game with a weighted roll or a bracket.
Compare our libraries Steam store pageTired of Black Mesa? The Swap tab finds the closest unowned games of the same type that are newer or rated higher.
Ready Up is a free tool: enter two Steam usernames and it lists the multiplayer games you both own, runs a bracket to pick one, and suggests new co-op games that fit how you both play. Ratings, tags and player counts from Steam and SteamSpy; updated 2026-09-08. Powered by Steam — not affiliated with or endorsed by Valve Corporation.