I love this game soooooo much- a few years ago I fell in love with FTL, but was slightly disappointed with the lack of actual tactical combat and ship construction- this game excels in both, and scratches the itch that FTL gave me!
Obviously because FTL is the closest game I can compare to, there's some features either from it or inspired by it that I would love to see in game. Obviously this game is not FTL and doesn't need any of its features, but it did some things right.
The features I had in mind are:
Peaceful merchant ships that you can trade with to unlock weapons, or add Surplus Ammo/Rockets/Batteries that could stack up in a Hanger Bay or something.
Optional systems accessed via rare warp-gates that have... harder enemies? Traders? Maybe an entire area with wrecked ships you can clear up for that little extra money/trading resources?
Force Arrows that you can toggle that are just a visual layer that shows the direction and amount of force an engine or railgun will inflict on the ship, so propulsion planning is less guesstimation and more careful planning. Maybe have another that shows how easily it would be able to navigate in any way- so you can tell before navigation that the tiny ships are better at strafing, but a longer one better at chasing.
AND FINALLY
Enemy ships fleeing either if they're overpowered by a certain percent, or their ship is damaged beyond a threshold. I.E. if you attack a ship, it'll attempt to either outright outrun you or spin up it's FTL drive and respawn just as damaged in the nearest system- and depending on timing, may be repaired by the time you get there?