Star Control 1 was one of the first games I played and it was fantastic. Star Control 2 I played much later and also enjoyed it quite a bit.
What I consider the core of a SC game? The arcade battles designs. Most importantly the ship design and the role of the planet's gravity well. It was actually the only feature common between SC1 and SC2.
The Earthling cruiser was about firing rockets accounting for trajectory while controlling the distance.
The VUX Intruder was about opportunistic salvo to either destroy the enemy ship or incapacitate its engines making it easy prey for later.
The Ilrath Avenger was also opportunistic ship but with a slight balance difference - the cloaking made it easier to get an opening but its salvos were not as devastating as the VUX
The Spahi was about hit-and-run tactics, slowly chipping your opponent's health away with your limited firepower and trying not to make too much mistakes.
The gravity well is what made VUX an Ilrath viable ships against a faster long-range opponent. The slingshot acceleration made the battles much less predictable and made it possible for a slower ship to outrun a faster one and devastate it with a short-range salvo. But it was counterbalanced with the associated risk of running head-first at the planet at top speed.
Overall I think the core of SC was that balance between the basic parameters of the ship design (speed, range, firepower, maneurability, defensive abilities) and the chaotic effect of the planet's gravity well, while also making the whole thing quite simple. Sure SC2 had story and cool aliens but so do plenty of Japanese visual novels. What made Star Control addictive were the battles. The sense of exploration, meeting quirky new races and growing power and alliances all built on top of that core game.
Actually I think SC2 made a mistake in making your main ship and the Chmmr Avatar too powerful as it took away the charm of the battles in the late game. So while I'm all for copying the SC2 exploration and race design would advise also paying very close attention to:
- Updating the arcade battles and extensively playtesting new ideas (e.g. more celestial objects, multiple ships in one battle, ect.) but making sure they don't take away from the simplicity and charm of the old battles which should be the golden standard to return to if something new doesn't work out.
- Analyzing the core ship strategies of SC1 and SC2 ships and making sure those core strategies are all viable in the new game (e.g. long-range sniping, fast hit/run, exploiting opportunities for a devastating short-range salvo, ect.)
- Letting the player customize and upgrade their flagship and fleet the way they want (no dumping you with useless free ships or forcing you to turn your flagship into a super-sniper)
- Making sure the endgame progression is balanced and keeps the early game strategies fun and viable (no super-snipers or devastating short-rangers with an overpowered tractor beam) Minor gradual upgrades to all ships that the AI has access to as well should work best. E.g. equipping the late-game VUX with a nerfed tractor beam while giving more max speed to the Earthling cruiser would keep the balance between them.