Ghost Ship's 2020 co-op shooter is four space dwarves mining in fully destructible procedural caves, and the destruction is the reason it works. Every wall can be dug through, so there is no level layout to memorise and no correct route - only the one you make. The four classes are genuinely interdependent: Engineer places platforms, Driller cuts tunnels, Gunner fires ziplines, and Scout has the grappling hook and the flares that are the only reason anyone can see. Missions have simple objectives and then a swarm arrives, and getting out is usually harder than getting in. It is a game about traversal under pressure, and the difficulty scales five hazard levels deep. Around it sits a well-judged progression of weapon overclocks, beards, and a space rig where you can dance and throw barrels for no reason at all. Ghost Ship kept adding free seasons for years after launch. Rock and Stone.