The story companions you get are really, horribly unoptimized (the fighter with 14STR/15CHA stands out), and they make the game harder than it should be for the higher difficulties. Probably if you stick to Normal you won't have any issues; it's a real struggle on Hard (and from what people say on the forums, borderline *mathematically impossible* on the highest difficulty, Unfair). On higher difficulties enemies get flat bonuses to every stat *and* roll, so expect to fight Kobolds with 26AC at level 2. Luckily the difficulty settings are very granular and you can adjust it to something slightly less brutal if you want.
It's very authentic Pathfinder, and while it's missing a lot of fun feats (no rapid reload!?), it's still a good time, if you enjoy the Pathfinder ruleset. If you're just interested in the story/kingdom-building I'd say probably stay away; this is a game that expects its combat to carry its weight. The combat *is* the best out of any modern CRPG I've played; Pillars, Tyranny, et al aren't even in the same ballpark.
Protip: in this game, flanking triggers if you're being attacked by two melee units; positioning doesn't play a role. This means your rogue can get sneak attacks without actually having to move behind the enemy. On the other hand, enemy rogues using ranged weapons get very easy sneak attacks on your tank, which can be rough.