We know currently we are limited to “Story” mode to do achievements. I would use a “known” pattern seen on many other games to manage that limitation:
3 game modes:
Tutorial: (achievements enabled)
the current “story” mode but imho should be much shorter, players should only play it one time to learn the game, and it should finish relatively early (target i’d say 4-6hours).
Standard: (achievements enabled)
3 preset difficulties: easy, normal, hard. No time limit, no custom settings or just few selected that don’t alter gameplay too much
Sandbox: (achievements disabled) (for personal testing purposes)
fully customizable parameters like it is now. Should also be lots of other parameters and changeable in-game. It could have a ingame “sandbox toolbar” for testing purposes (hire 100% employee, set business traffic index… etc)