1. A modern multi-user dungeon game, all text-based, that would be functionally like many LPMuds[0] in almost every sense, but with a high-quality commercial (but non-evil) backing and/or several hundred or thousand players online at every time of the day.
2. Elite: Dangerous with 90% less grind.
3. A million more variations of Dwarf Fortress. It's an amazing concept.
4. CRPGs that could capture lightning in the bottle in the same way that the Ultima series did in the 90s.
5. A civilization simulation with such detail that you could base serious policy decisions on how things work out with different political settings.
2. Elite: Dangerous with 90% less grind.
3. A million more variations of Dwarf Fortress. It's an amazing concept.
4. CRPGs that could capture lightning in the bottle in the same way that the Ultima series did in the 90s.
5. A civilization simulation with such detail that you could base serious policy decisions on how things work out with different political settings.
[0] https://naga.icesus.org/icesus/ being my personal favourite