I don't see what space there is to add anything to this game. Any "expansion" would probably have to start replacing the base game deck, rather than just adding cards to it. It's just not a very good game. You can tell this by the fact Marco gave it a negative review, which very rarely happens.

it's just "fine" and that was probably the idea given FFG's strategy. make it baaaarely good enough for fans and/or people willing to pay more money for more cards/better and more differentiated gameplay

I bought it even though I don't like Star Wars and get bored with card row deckbuilding games (i.e. deckbuilders other than Dominion) quickly, despite liking them. I don't really regret trying it, it's affordable enough despite the IP markup. It's actually kind of fun figuring out why the game doesn't work, if you like that sort of thing haha. You might play 10 or so times, unless you have a child in your family who likes Star Wars and might want to play it some additional times. I'm probably giving it to my nephew, which is a win for me since he'll get extra enjoyment out of it. The coolest part of the game is the bases, though those are also swingy (but a fixed deck, so deck knowledge will make this aspect of the game more predictable). I think the base mechanic adds some depth that is crucially missing from Star Realms. On the other hand, force is underbaked and the faction specific cards without combo potential make the game scripted, and mean the best strategy is "I hope I draw my best cards."