The main story is about 20ish hours long, but if you are bad or not paying attention, you will die...like a lot. The enemies can kill you in 2-3 hits on normal. The game does get a bit too easy on normal as you get close to the end, because if you gather and graft lot, you'll hav loads of martial to craft arrows and traps and health potions. The "dialogue choices" aren't really much of choices because it all ends the same way. It's just if you wanna be a slightly differs personalty. Aloy is basically Lara Croft, but more caring and kills robot dinosaurs.