I really like Imperial Settlers, but Iād tentatively recommend the 51st State Master Set over it, even though I like IS better. 51st State came first and itās the same kind of gameplay but everyoneās playing from a common card pool. IS is kind of hard to get into because everyoneās deck is trying to do different things in different ways, and while I prefer that overall, it makes it quite a bit harder to learn.
Also Iāve got a handful of expansions for IS and I never play them because itās too much faff to swap cards in and out of the different decks.
Thereās a roll and write Imperial Settlers game now. I havenāt looked into it but that might be a good compromise too.