The low-spoiler guide at Nice Game Hints for Four Last Things gives you just enough hints to get past that one blocker in a puzzle. The hints are served at the external server as it supports better the way to reveal information gradually. You will finally see the solution to the puzzles after a red spoiler button.

Includes also hints (and solutions) for achievements.

https://www.nicegamehints.com/guide/four-last-things/