I'm looking for a new colony sim on PC. What I've played so far are:
Rimworld
Oxygen Not Included
Banished
Timberworld
Frostpunk
Anno 1800
I know some of these might not be strictly colony sims. What I'm really looking forward to is Manor Lords, but we don't have a definite release date on that.
Same, I like playing railworlds but I always get stuck when I start expanding my railway network because there aren't enough resources for the expansion to pay for itself.
But there are essentially unlimited amounts of resources out there and patches grow the further you get away from the starting location. Just go in any direction and you'll stumble upon resources patches in the double or triple digit millions quite quickly.
If you struggle with the biters, you can turn those down a notch or two (or turn them peaceful or non existent even).