Probably you have played the old Star Wars Rebellion game, there is a good GOG version which it can be ran without too many problems in a modern computer.
I saw without too many because you will need use dgVoodoo2 if you want see the correct graphics in battles. Just download it and copy the files from the folder MS inside the main Rebellion folder.
Just with it you can play this very old game with more of 20 years in its back. It is a poor graphics game, it is true, it was poor even when it was released but it is unique and very fun.
The unique modern game when you can make the same would be the Star Wars Empire at War from Steam+my mod FOC Alliance Rebellion where you have special Galactic Conquest where you can search heroes, research everything and play with more new features from that game.
The Steam EAW version is fully neccesary because it is different to the others thanks to the last patches added by Petroglyph only to this version.
The EAW with the mod is very fun but for me the old game never was bad and sometimes, I play it. This time, I have played it with a mod, this is a thing that I did not discovered before the game was released at GOG. Perhaps I did not search too much, who knows.
The mod added is named SW Rebellion - Balancing & Graphics Mod (v5) and this is the main list of changes.
-troops can't be bombed anymore (except war droids), so you have to battle them with your own troops (that increases the meaning of troops and their stats, now you have to deal more with troop transports and troop vs troop fighting)
(if you want to bomb troops again, take one of the files from the folder 'bombable troops') (the AI can't deal with this new concept and sometimes bombs a planet again and again and again and try to destroy the troops via bombing, but can't due to the mod (in this case, you can dissolve the troops manually to 'help' the AI or you take one of the 'bombable troops' files before starting a game to prevent this case))
-most fighter and troop capacity's are halfed (you need to build more transport units and tactical combat are not only fighter battles anymore)
(at game start some ships will have to much fighters and troops aboard, because reduction of capacity isn't considered at game start by the game -> so reduce them manually)
-bomber are a little bit weaker (less laser weapons and more ion cannons) against other fighters, but stronger against capital ships
-the a-wing has no hyperdrive anymore, but is relativ low on cost (the a-wing was always a little bit "unrealistic" in the star wars universe, this little a-wing had too many features, it makes more sense as short fast interceptor and that's the role it now has in the game -> no hyperdrive and cheaper, the a-wing is still the best choice on alliance side for fighter vs fighter)
-also all laser armament (anit-fighter) on the capital ships are reduced by nearly 50%, because there are less fighters in the battles now (the reduced laser amount is regiven as turbolasers to the ships)
-all ship stats are redone and (hopefully) balanced, also all ships now have a function (no more useless ships)
some exapmles for some special changes:
-> the imperial assault cruiser seems to have a low amount of weapons, but have the highest fire rate in the game (the weapon recharge rate stands in direkt relation to the fire angle with the highest total number of all three weapon types)
-> the mc90 cruiser has mainly ion cannons and is low on turbolasers (so he isn't that effective against ship's hull), but has a high firerate, very good damage control and strong shields
-> imperial star destroyers seems to have very strong shields, but also have a low shield recharge rate, which results in a constant shield loss if it's continous bombarded
-> the assault frigate has a very low production cost for it's size and values, but a high maintaince cost, so it's a ship for short terms, if you need quickly some medium battleships
-almost all ships have got a new 3D model (don't be irritated because the models sometimes seems a little bit inconsistent if you look close at them, but the old engine of the game is to bad to give us better results)
-also put in many new ships (for example: allegiance star desroyer, mc90 cruiser, imperial assault cruiser, dominator interdictor, home 1 star cruiser, nebulon-b 2 frigate, golan 3 station)
-every side has now one spacestation that can't travel through hyperspace, but has strong firepower and relativ low maintaince cost
-all interdictor cruiser are much more expensive, especially on maintaince, now you have to think about where to use this ships and not only building many interdictors and every fight has to be a last men standing when interdictors are researched
-also some ships are available for both sides now
-special forces & character stats have also been changed (special forces are more expensive, special forces and main chars have now a little bit variance on their stats, research ability of chars with research capacity were decreased by 50%)
-it needs more time to research and you have more things to research (some units are available at game start, but have to be resarched first to build them, for example: stormtroopers, mc40 light cruiser, kdy ion cannon)
-also the stats of defenses & facility's have been changed (gencore level 2 can also fire at bombing ships and troops now, level two buildings incrases building speed only by 50% anymore)
-coruscant has now the most energy points by far
-in tactical battles you can't see anymore which units are on your own or your opponents ships, you only will see that's something on the ship, but don't know exactly what it is
(make it a little bit more difficult for the enemy to know which ships to hit first to kill your commanders or so (but yes, you still can see who is aboard ships in the battlescreen before battle is starting, so it's only a little advantage))
(this can be redone with the file in the folder 'visible units') (it wasn't possible to change the game the way, that only your opponent doesn't see the units or that you can't see the units in the battlescreen -> some pics are shared with other functions in the game)
As you can read, there are a lot of new additions, many changes in the main game, even some new units and new models.
I have recorded a small video. Very fun, even if the 3D combat is not looking 100% perfect because the game is too old and it can not be better.
I was curious lately because Disney announced a new Strategy game. I will wait with many curiosity what they are developing.