Considering my history here, now that the guidelines have expanded it seems only right that I do this 
極限脱出 9時間9人9の扉 (Zero Escape: 999)
Developer: Chunsoft, Regista, & Spike Chunsoft
VNDB Play Time: 21h45m
VNDB Link: Kyokugen Dasshutsu - 9-Jikan 9-Nin 9 no Tobira | vndb
Character count: unknown, estimated 348k-413k from vndb times
Number of weeks to finish: ~14-17 (estimated from above character count)
Summary
Kidnapped and taken to an unfamiliar location, nine people find themselves forced to participate in a diabolical Nonary Game by an enigmatic mastermind called Zero. Why were they there? Why were they chosen to put their lives on the line? And more importantly, who can be trusted?
more specific summary (not super spoilery but just in case):
Nine people have been kidnapped by a mysterious person called Zero and are forced to participate in a survival game called the “Nonary Game”. Each player has a bracelet numbered 1–9, which they must use to pass through doors numbered 1–9 to reach the exit before 9 hours run out and the ship in which they are in sinks. Various puzzles must be solved in order to advance through the ship and reach the exit, while uncovering the mysteries behind the Nonary Game.
Availability
Steam (includes second game)
PS4 (includes second game)
XBox (includes second game)
DS (original version, not voiced)
PS Vita (includes second game)
mobile version technically exists but is weird apparently
Personal Opinion
999 was the first long-form thing I read in Japanese and I had a wonderful time with it! It’s the sort of thing that drags you along for the ride desperate to know what’s going on, which I think is really good for motivation. If you enjoy other mystery death game puzzley sorts of things I’d definitely recommend it (Spike Chunsoft is also known for such things as Danganronpa, AI: The Somnium Files, and Steins;Gate if that’s any indication); it’s also on the more well-known side as VNs go which could be cool. Schedule-wise I think it’d be pretty easy to figure out as well considering the structure of it, and I certainly have insight to provide there 
Also don’t let the idea of sequel games scare you off, they’re there for you if you enjoy the first one but 999 can absolutely stand on its own.
Pros and Cons for the Book Club
Pros
- Most dialogue voiced
- I believe text-hookable? I used game2text so
- Clear structure
- Well-known good old fun mystery VN! (8.29 on vndb)
- Puzzles if you’re into that sort of thing
- Available a lot of places apparently
- Good balance of dialogue and narrative for reading practice (though there is a dialogue-only option if that appeals to you)
Cons
- Not fully voiced
- Covers a pretty wide breadth of topics, though weird vocabulary asides tend to be short-lived
- Older style reading interface if that bothers you (see screenshots)
- On the more expensive side, but it’s on sale like every other week it seems like
- Definitely dark if you’re not into that
- Puzzles if that’s not your thing
Pictures
Difficulty Poll
How much effort would you need to read this VN?
- No effort at all
- Minimal effort
- Moderate effort
- Significant effort
- So much effort my head might explode
- I don’t know
0 voters