Actual teamwork and an encouraging community that I actually want to play public games with: this is probably the best co-op shooter that's been released since L4D2. There's "live service game" features, but they're all free and the only micro-transactions for the game is the cosmetics you see in the DLC section; which you really don't need because they're just extras on top of the ones you can unlock in game. Anything you miss from a season can still be unlocked too. The "season pass" is entirely free and is just another thing for you to progress through, all being free cosmetics. Really puts the likes of Destiny to shame. The game's also the absolute best cave expedition game I can think of, nothing comes close to this.

Pretty much a must play, even if you play it singleplayer honestly. Also if you use the mod "More Players Balanced" you can break the player cap, and then with 10+ players on a high difficulty DRG becomes my favourite online game.