I've recently played games like Uncle Chop's Rocket Shop and Tin Can, which have interesting in-game manuals that are required for gameplay and contain complicated/esoteric information. Other games that I've played:

• Tunic
• Keep Talking and Nobody Explodes
• DCS: World
• Zachtronics programming games

I was wondering if there were any other games people can think of, with complex and information-dense manuals that contain lots of puzzles and secrets. Thanks!