must be one vs Teach the Thief

must be one is a number puzzle built on a single rule — the one in its name. A grid of numbers. Four operators. Combine neighboring tiles with arithmetic and collapse the whole board down to a single 1. That's the entire game: all becomes one. It reads as obvious for about three moves. Then it doesn't. - One rule, no filler — no twenty-minute tutorial, no menus to dig through. You understand it in seconds and spend the rest of your time actually thinking. - Always solvable — every stage is generated so that a solution is guaranteed to exist before you ever see it. If you're stuck, that's on you, not the board. - A climb that keeps widening — early stages stay in single digits; later ones open the range up and the arithmetic gets meaner. - Free, and quick to pick up. One stage on the train; look up an hour later. From office-canard — a one-person studio making small, system-first games. If this one gets its hooks in, there are more small games where it came from.

Meet Pip: small paws, big plans, and a weakness for shiny things. In Teach the Thief, every heist starts with two choices. Pick two treasures that share a color, a shape, or both, then watch Pip scoop up everything that matches. The trick? Make every grab count—and leave the protected treasure alone. A LITTLE CHOICE. A BIG HAUL. Match different shapes of the same color to collect that color. Match the same shape in different colors to collect that shape. Match both to narrow the haul. Preview exactly what Pip will steal before you commit. 50 HEISTS TO OUTSMART Explore a playful museum map full of bite-sized puzzles. Plan around protected pieces, preserve useful pairs, and clear each board within your grabs. LEARN WITH PIP A hands-on Level Zero tutorial walks you through the basics. Experiment with free undo, restart, and hints as you find your way to the perfect heist. DRESS FOR THE JOB Earn Rose after Heist 4 and Midnight after Heist 15. Or give Pip a new look with optional King, Wizard, Pirate, Astronaut, Detective, and Chef outfits. Your equipped outfit follows Pip throughout the game, from peeking over the board to taking a well-earned nap. PLAY AT YOUR PACE No timers. No account required. Just you, Pip, and one more clever little heist. Teach the Thief is free to play with ads after Heist 3 and later heists. A one-time No Ads purchase removes ads. Additional outfits are optional one-time purchases.