Occupy White Walls is an online, multiplayer sandbox game where you design and curate your own virtual gallery. The game has a wide variety of classical art from all periods, but it also has art from contemporary artists including some of the players of the game itself. I’ve been so lucky as to have become one of said users, having my art added to the game for other players to potentially add to their own virtual galleries.
Best part is that the game is free, and has no in-game purchases; from my understanding, there won’t be any in the future, either. So, check it out, and most importantly, put my art up in your gallery.