Minecraft wiki entry for Markus_Persson, associated text: Legend of the Chambered, a dungeon crawler containing many textures that were reused in Minecraft.
Prelude of the Chambered, an escape game Notch made in 48 hours for Ludum Dare 21.
First person shooter prototype in flash (Archived here)
Flash doom level renderer (Archived here)
Dungeon master type game engine in Java (Flash version uses static graphics) (Archived here)