One Room Dungeon is a PICO-8 game by Armor Games.

Explore a mysterious and exciting dungeon filled with exciting mysteries without ever leaving the same room! Why would you change rooms when clearly this one has all the danger and excitement and danger that one could possibly need?! Come to the One Room Dungeon, live the rest of your newly mysterious-and-exciting life there, and see how far you will go in the One Room Dungeon!