I'm immediately apprehensive when the developer resorts to listing how many of a given "thing" is in their game. To me, it's a sure-fire mark of poor quality. Thirty quests? Can't be a very long game then, that's really not much content.
why not look at some gameplay videos or reviews or maybe judge the game by trying it because i am having a ton of fun playing it and i dont play many games these days, i have played for 4 hours and only finished 3 quests so far, if i were to guess i would say minimum 20 hours of content and maybe as much as 30 hours also the dev is very active in the steam forums answering questions and is fixing bugs as soon as they are reported with several patches a day so far.
https://youtu.be/DqQOOOqFc7Y
https://www.youtube.com/watch?v=m_thX45ikgY