MONOMOON Guide
MONOMOON is Gentle Giant's exploration puzzle game, a Metroidbrainia without proper instructions. You explore freely, discovering items, secrets, and hidden mechanics to work out your next goal.
This site gives answers by puzzle and item: Red Door puzzles, elevators, items and achievements.
Top Guides
How MONOMOON Works
MONOMOON progresses through exploration and discovery, with every puzzle clue available inside the game.
- The main game takes about 10 hours, with more secrets after the credits.
- Progression is nonlinear: you choose where to explore next.
- You can slide down at the opening's downward arrow.
- Checkpoints also let you fast travel.
- Inserting the moon at the top of the map reveals a grid.
- The Tome contains information you can apply at key locations.
- Some rooms require knowledge or a visit elsewhere before you can solve them.
When stuck, check unexplored map openings, inactive checkpoints, and buttons. Revisit Tome pages you haven't understood, then explore elsewhere if a room offers no further progress.
Use the MONOMOON walkthrough for exploration help, or the elevator puzzle guide for coordinate input.
Walkthrough
Find the puzzle you are stuck on in the MONOMOON walkthrough.
Red Door Puzzles
Red Door puzzle 2's answer is 12: count turns, excluding the initial straight movement. The Red Door puzzle answers cover all nine puzzles.
Elevator Puzzle
Enter each elevator room's vertical coordinate into the two grids to activate elevators. The elevator puzzle guide explains how to read those coordinates.
For the diamond grid puzzle, match the Tome page borders to the grid. The electric purple blocks puzzle requires one block outside and two on the buttons.
Items and Achievements
MONOMOON has 15 achievements, including 14 initially hidden achievements.
Achievements
Scales and MONOMOON have the lowest global unlock rates, both 0.2%; Wanderlust follows at 1.0%. These rates are from November 12, 2026. Their conditions are finding the Scales, reaching The End, and activating the Seeker, respectively.
The MONOMOON achievements guide lists all 15 conditions.
Items
Find Sea Emblem, Earth Emblem, Sky Emblem, Amulet, Wand, Hourglass, Fruit, Skull, Crown, Mirror, Scales, Tome, and Seeker.
The items and upgrades guide lists these 13 objects and their achievement conditions. Find Tome pages 12 and 13 along the route to the rightmost telescope. Get fire from the green dragon. There is no jump upgrade: no double jump, no wall climb.
FAQ
All MONOMOON puzzles can be completed solo, and external tools are unnecessary.
Yes, full controller support is available, and testers completed everything with controllers and Steam Deck. Some sections are trickier with a controller; keyboard and mouse are the recommended controls.
No, translating the language is optional and never blocks puzzles or progression. You do need to understand number symbols for some late-game puzzles.
Yes, you can complete the entire game alone, including every post-game puzzle.
No, you can solve everything inside the game. Screenshots or paper notes help with a few later puzzles.
Check unexplored map openings, inactive checkpoints, and buttons, then reread Tome pages for clues. Some rooms require visiting elsewhere first; use the walkthrough to find relevant progression help.