Discord has so many features that make it feel like it was made by and for gamers. Like the "currently playing" statuses, or "streamer mode" that hides identifying info when you have OBS open. It also works better than anything else for large communities with its roles/notifications system. It has a good design but I don't see it as particularly playful, just really well executed
There are random joke-lines when you open the program. Also the logo is funny. That's about it for fun, but I think the joke-lines are there just to deviate attention from the fact that discord updates every 2 or 3 days which is annooying.