If there is one game i could play forever it would easily be Gmod. On the surface this game is basic but its the community that makes this game, you open up the workshop to see people pour their heart and soul into some mods or a quick 10 minute job for others (check out arc9 EFT guns they are the best ones on the workshop) and with these mods you can turn gmod into anything, wanna recreate D-day just install the right mods at the click of a Button, wanna watch people explode check zippy's gore mod. This game has something not alot of other games can recreate, a community that loves its platform and for those who try to compare this to games like roblox, I ask you this in roblox can you wield a glock 17 and kill an army of furries with a picture of Hitler on the side of your gun or join a multiplayer roleplay server where the whole gimmick is to make drugs and kill the 8yo kid for all his money because he hasnt worked out how a bank works yet. so yes this game is a game I could play forever due to how vast the community and the mods that come with the workshop are. so if you are ever looking for a game to play with friends or hell evem by yourself then Gmod is the game for you.