This one’s kind of my favorite. You design your colonies, you design your spaceships, you even design your diplomatic contracts, allowing for some pretty interesting negotiations.
The ways to deal with opposing factions were just as varied, from covert spy sabotage missions, through overt attacks with ships and swarms of missiles (some nice variety there too), you could even drive whole colonies/asteroids into one another.
Not an easy game though, and the fixed realtime meant alternating calm downtimes with panic-filled chaos when everything went wrong at the same time.
This game taught me basics of hex edit hacking for money. Not having to sell your key resources helps a lot, but even when cheating, the game can be a handful. And autohotkey scripts to automate common tasks were a godsend.