You are trapped inside an abandoned arena, where monsters now constantly spawn,
You only have a stone sword, but you HAVE to slay  TEN monsters to get an upgrade! or new weapons, armor, or tools!
The upgrades you get are randomly generated, and you only get them after you kill TEN monsters that randomly spawn around you. you can get upgrades like better swords, new abilities, and better armor. the monsters get progressively stronger but only by a little bit, every time you get an upgrade.