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


I believe in Deaths Door, we had to gather pages that explained the game mechanics, but by the time you got the pages it was moot point. Tho I might mixing up some games.
I don’t remember a manual in game for Death’s Door. It’s a good game, though.
Are you mixing it up with TUNIC?