Short, turn-based, text-mode strategy games. Each command is a real concept; play well and you'll have used the idea, not just read it.
One tank of delta-v and a planet that will not wait. Leave early and the burn costs double; forget the capture burn and you fly past Mars forever.
Coordinate innate defence, helper T-cells, antibodies and cytotoxic T-cells against a mutating pathogen — while your own inflammation threatens the organs you're defending.
Han China has fractured into warlords and your writ reaches exactly as far as your grain does. March past the granaries and the campaign that looked decisive destroys your own army.
Set interest rates each quarter as inflation, jobs and confidence swing against you. Every move lands two quarters late — steer by the windscreen, not the mirror.