Pixel unDungeon is a small patch on top of Pixel Dungeon, a traditional roguelike game with pixel-art graphics and a simple interface. Developed by Shai Ayal, this game is available for free on the Android platform under the Games category, specifically the Role Playing subcategory.

This game is notoriously difficult and luck-based, causing many players to die frequently. However, Pixel unDungeon offers an undo button in the in-game menu, which is available even after death. Pressing the undo button will take you back 10 turns in time, allowing players to reduce frustration and strategize better. It's important to note that if you choose to exit the game or return to the menu after dying, the game will be over permanently.