TOKYO JUNGLE!!!! Its such a fantastic game! Its a survival game that takes place in tokyo yeeeeeeeaaaaaaaaaaaaaaaaaarrrrrrrrssssssss into the future, after all of humanity "mysteriously" disappeared and all of the animals from zoos and whatnot + plantlife took over. I love the story, plus it has a multiplayer mode. You can choose from any animal you'd like, and theres so many small details that really make it its own, and there really hasnt been anything like it since imo! It has a very, gritty yet fresh feel to it too.
Not as obscure anymore, but Lobotomy Corporation too! Imagine the SCP foundatation as a SUPER difficult monster management game with incredibly deep lore. The series has a sequel, webcomic, webnovel, and much more content!