10 hours is a little less that i would like to be honest. in games like these i really like it when it takes longer, because it makes me feel at the end that i went a far way from where i started, it helps with that sense of adventure. like in TLoU, it feels like you look back at the start and is like "yeah... i came a long way since that!"
10 hours is my bare minimum i guess. If they are able to keep the pace of the game up and mix up the gameplay then as long as possible is always best. I just dont want it to be super short (>=8 hours) or overly long with weak pacing and repetitive gameplay.