No game with the name "Puzzle Ring" could be found. A puzzle ring is part of the game "Diablo III". This game must be purchased either online or through a store. It can then be installed on one's computer and can be played alone or with multiple players online.

It's probably the Jigsaw Puzzle.

An adventure game is a computer or video game based on investigation, exploring, and puzzle-solving through interaction with game characters, with a focus on narrative rather than reflex.

The paper in the castle courtyard should help you.

The computer puzzle was so complex that none of us could work it out.

The computer puzzle was so difficult that none of us could work it out.

The computer puzzle was so challenging that none of us could work it out.