I never thought, that i will spent almost the whole week just completing the all 56 chapters there is now, and damn, it totally was worth the time. You won't see that much projects like that one, keep it up
Chapter length varies. The first 10 or so go by very quickly, but length picks up significantly afterwards. Depending on reading speed, you've got about 40-60 hours of content here to enjoy.
Afterwards, if you still want more, a replay of the game will show you just how much of the story was expertly foreshadowed. There's a youtube playlist of the soundtrack which has all music, including originals, and the discord is active with Work in Progress renders for upcoming chapters.