RPGFS is an experimental game that combines Linux filesystem commands with an RPG. The filesystem is the environment, files are paths, bugs, and items. The goal is to find a special file in the filesystem and remove it to enable a command to destroy the filesystem. Available commands include cd (to navigate the filesystem), pwd, ls, cat (to inspect files) and rm (to remove/attack files). Can't say it's enjoyable, but it was an idea I wanted to see in code.
SWIM! is an experimental game originally conceived by Ben Brown and Dakota Smith to test ideas we had about in-game motivation and the concept of endless but ultimately futile gameplay.
Addiction is not about what you DO, but what you DON'T DO because of the replacement of the addictive behavior. The reason why what defines addiction for one person may not define addiction for another person, even given quantified equal stretches of time action or consumption, is because addiction is not about the action, but about the individual person. This is why merely resisting addiction of any kind is not enough. This is why -- although some activities are more broadly compelling than others -- virtually any activity can become an addiction. What addictive behavior does is reveal underlying anxiety (and often depression, which itself is nebulous) and lack of desire to perform the things we're "supposed to" be doing.
Programming-style puzzle game. Give commands to your robot to light up the factory.