Here’s a couple of examples Keep talking and nobody explodes — The most popular in the list I think
Uncle Chop’s rocket shop — the game where you are repairing your client’s rockets by following the in-game guidebook
Tin can — here you are also repairing the spaceshp but this time you are it’s capitan and you are in space in the middle of nowhere


Not really a manual, but more of a 4th wall derailment into a fever dream of sorts? With a lot of reading while navigating a mystery? And some match 3 tower defence action in between?
Titanium court.
For more of a game with an actual manual focus, try - King of the Bridge. It’s a game about chess. Mostly.
Oh! I’m absolutely loving Titanium Court, I’ve been playing it on and off for a couple of weeks, now. I’ve only recently gotten to Chapter 2!