Rover missions
What is this all about: exploring deadly non-colonized planets using remote-control programmable ground rovers.
How: rovers are a resource to trade at the nearby planets, rovers can be «grid bugs» or support arbitrary rotation, they can do measurements than don't make much sense to the player. There is a Lua API, «execute on the rover» function and a special mode displaying rover position and known obstacles; there are bindings to execute single-step commands on the rover.
Why (in-universe): one of the drives towards MC was the idea of one-way survey missions to deadly planets; the mechanical parts of the rover were expected to break down before the computation parts and the communication parts. For an MC fully escaping via a radio channel is feasible and there are no moral problems about killing the explorers and bringing mere copies back. (Here should be a text about traumatic amnesia, suspending inter-hemisphere link in humans using drugs, and selection of MCs who are willing to use temporary access to extra CPU power to run a part of self). Of course, Events We Know About have happened, and the sad planetary geologists are trying to run robots using weaker controlling software. When someone offers to get the data they want by controlling rovers from an orbit around a planet nobody has any reason to visit, they don't ask too many questions.
Why (game mechanics): ROT13 still puts an entry barrier. Rover mini-game allows a learning curve from running the mazes manually to recording simple keyboard macros to writing simple scripts to writing actual algorithms with some plot justification and without being too far from the general game atmosphere.