a trip to the Warpspawn games site might net you what you are looking for.
( family friendly but old-school link:
https://www.angelfire.com/game...rpspawn/SFgames.html )
Also, the Free Wargames Rules wiki
(
https://freewargamesrules.fand...gory:Science_Fiction )
Depending on your preferred level of complexity and access to old materials, I might throw in a few more suggestions.
Starfleet Battles has a free version that is eminently playable.
Alternity is freely available and has a ship combat thingy.
Voidstriker has vector movement and interesting concepts, I believe it has a free version as well.
Simply using Risus with teaming-up rules might be what you're looking for.
On the crunchier side, the big robot thing game$ have passable freely available packs as well.
In any case, I am a proponent of each player having their own starfighter/mech while the big ship is their base, as this mode of play doesn't fall apart if one player doesn't show up.
This message was last edited by the user at 10:34, Fri 12 Aug 2022.