#5
Synced offers something the rest of this list mostly doesn't — a contained, purpose-built three-player co-op PvE mode called Gear Up, where you and two teammates fight AI waves and boss encounters using a Nano companion system that creates real build synergy between players. It's not trying to be a live-service behemoth. Sessions are focused, the mechanics are approachable, and the core co-op loop is fully free with no pay-for-power barriers. The community is smaller than the games above it, so matchmaking relies more on premade squads. But if you have two friends and want action co-op that doesn't demand 200 hours of learning before it clicks, Synced delivers a cleaner drop-in experience than most games on this list.