As my January personal code project, I created an experimental game that considered what would happen if you crossed an RPG with a UNIX filesystem. The result is RPGFS.
You have some simple commands available (ls, cd, pwd, rm) and you fight "bugs" in the filsystem using the rm command (everything is a file). You also consume "items" with rm. The goal is to descend the filesystem to find a special file to unlock another command to destroy the filesystem.
This was written as part of a monthly project I'm undertaking in 2014, and represented a small amount of work (hack). It's written in C for Linux, and you can grab it at the URL if interested.