Thermo Sudoku in IOS

by Cracking the Cryptic

Walkthrough, Guilds, Tips on this special game

Our Site Score

87/100

Thermo Sudoku is a brilliant evolution of the classic Sudoku format. For those who find standard Sudoku a bit repetitive, the 'Thermometer' constraint adds a visual, logical layer that completely changes how you view the grid. Numbers must increase as they move away from the bulb of the thermometer, which immediately narrows down possibilities in a very satisfying way.

This app is part of the 'Cracking the Cryptic' collection, meaning the puzzles are hand-crafted by master setters rather than being generated by a computer. This results in a 'logical flow' where you feel like you're following a breadcrumb trail left by the creator. The UI is clean, professional, and includes the essential 'note-taking' tools that serious solvers need. It’s an intellectual treat.

Reviewed on: Thu Feb 26 2026
Dinsun Avatar

Dinsun Review

Now this is how you make a puzzle game. No ads, no nonsense, just brilliant logic. The 'Thermo' gimmick isn't a gimmick at all—it fundamentally changes how you look at the board, creating elegant solve paths that normal Sudoku can't touch. The UI is perfectly optimized for power users, with precise note-taking tools. It’s a premium experience for people who actually want to use their brains. It’s niche, sure, but in its niche, it’s nearly perfect.

Overall Stats

Pros & Cons

  • Impeccable puzzle design
  • Clean, professional UX
  • Extremely high difficulty curve
  • Minimalist presentation might be too dry for some

Technical Report

Performance: Flawless performance; excellent implementation of Sudoku note-taking tools.

Accessibility:

    Audience Fit

    Buy if: You are a logic puzzle enthusiast who finds regular Sudoku too simple.

    Skip if: You prefer casual, mindless matching games.

    Similar Games:
    • 1488838275
    • 1509121515

    Reviewer Context

    • Reviewer: Dinsun, 40-year-old conservative gamer
    • Hardware: iPhone 15 Pro
    • Playtime: 8 hours
    • Status: Completed all 'Medium' puzzles

    The Game

    Available on: iPhone, iPad, iPod

    Version 1.4Fri Apr 01 2022

    20 new puzzles, 100 puzzles total!


    ***** MARCH UPDATE *****

    20 new puzzles, 100 puzzles total!

    -------------------------------------

    Presented by Cracking The Cryptic, YouTube’s most popular Sudoku channel, comes a new game featuring one of the most popular puzzle types: Thermo Sudoku.

    How does Thermo Sudoku work? Well each sudoku grid contains thermometer shapes (often drawn to create themes) and digits on thermometers must increase as one moves further from the bulb end. The interactions between the thermometers leads to new logical ideas and patterns that completely refreshes the standard sudoku solving experience.

    As with their other games (‘Classic Sudoku’, ‘Sandwich Sudoku’ and ‘Chess Sudoku’), Simon Anthony and Mark Goodliffe (the hosts of Cracking The Cryptic) have personally crafted the hints for the puzzles. So you know that every puzzle has been play-tested by a human being to ensure that the sudoku is interesting and fun to solve.

    In Cracking The Cryptic’s games, players start with zero stars and earn stars by solving puzzles. The more puzzles you solve, the more stars you earn and the more puzzles you get to play. Only the most dedicated (and cleverest) sudoku players will finish all the puzzles. Of course the difficulty is carefully calibrated to ensure lots of puzzles at every level (from easy through to extreme). Anyone familiar with their YouTube channel will know that Simon and Mark take pride in teaching viewers to be better solvers and, in these games, they always craft the puzzles with the mindset of trying to help solvers improve their skills.

    Mark and Simon have both represented the UK many times at the World Sudoku Championship and you can find more of their puzzles (and lots of others) on the internet’s biggest sudoku channel Cracking The Cryptic.

    Features:

    100 beautiful puzzles

    Hints crafted by Simon and Mark!


    Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch.

    ***** MARCH UPDATE *****

    20 new puzzles, 100 puzzles total!

    -------------------------------------

    Presented by Cracking The Cryptic, YouTube’s most popular Sudoku channel, comes a new game featuring one of the most popular puzzle types: Thermo Sudoku.

    How does Thermo Sudoku work? Well each sudoku grid contains thermometer shapes (often drawn to create themes) and digits on thermometers must increase as one moves further from the bulb end. The interactions between the thermometers leads to new logical ideas and patterns that completely refreshes the standard sudoku solving experience.

    As with their other games (‘Classic Sudoku’, ‘Sandwich Sudoku’ and ‘Chess Sudoku’), Simon Anthony and Mark Goodliffe (the hosts of Cracking The Cryptic) have personally crafted the hints for the puzzles. So you know that every puzzle has been play-tested by a human being to ensure that the sudoku is interesting and fun to solve.

    In Cracking The Cryptic’s games, players start with zero stars and earn stars by solving puzzles. The more puzzles you solve, the more stars you earn and the more puzzles you get to play. Only the most dedicated (and cleverest) sudoku players will finish all the puzzles. Of course the difficulty is carefully calibrated to ensure lots of puzzles at every level (from easy through to extreme). Anyone familiar with their YouTube channel will know that Simon and Mark take pride in teaching viewers to be better solvers and, in these games, they always craft the puzzles with the mindset of trying to help solvers improve their skills.

    Mark and Simon have both represented the UK many times at the World Sudoku Championship and you can find more of their puzzles (and lots of others) on the internet’s biggest sudoku channel Cracking The Cryptic.

    Features:

    100 beautiful puzzles

    Hints crafted by Simon and Mark!


    Ratings & Reviews

    4.8 out of 5 with 145 Counts
    Age Rating 4+

    Screenshots

    Thermo Sudoku screenshot 1Thermo Sudoku screenshot 2Thermo Sudoku screenshot 3Thermo Sudoku screenshot 4Thermo Sudoku screenshot 5Thermo Sudoku screenshot 6

    Thermo Sudoku introduces a unique twist to the classic puzzle. Each grid contains thermometer shapes; digits placed on a thermometer must increase in value starting from the bulb end. This simple rule creates deep logical deductions. Developed by the experts at Cracking the Cryptic, this app features puzzles that have been featured on their popular YouTube channel, ensuring a premium, hand-crafted experience for every solver.

    Features

    1

    100+ Hand-Crafted Puzzles

    2

    Hint System by Logic Experts

    3

    Smooth, Modern Interface

    4

    Undo/Redo and Note Tracking

    Tips

    Promotion Videos

    All the Fun of Thermo Sudoku - YouTube

    Related Videos

    Gameplays

    Q&A

    The app starts with an interactive tutorial and easier levels, making it accessible to anyone who knows basic Sudoku rules.

    More by Developer

    85
    72
    Arrow Sudoku
    Last Update: Thu May 12 2022

    You Might Also Like

    All Categories

    Puzzle Game

    Action Game

    Simulation Game

    Casual Game

    Adventure Game

    Card Game

    Roleplaying Game

    Board Game

    Sports Game

    Strategy Game

    Racing Game

    Family Game

    Casino Game

    Music Game

    Word Game

    Trivia Game

    Education Game

    Games Game

    Entertainment Game

    Utilities Game

    Social Networking Game

    Books Game

    Health & Fitness Game

    Lifestyle Game