Thinking

A logic puzzle. Nine black blocks, lettered A to I, sit in a 3 x 3 grid. Each number from 1 to 6 flips three blocks in its own secret way: a black block turns purple and a purple one turns back to black. Choose numbers one at a time, watch which blocks turn over, and work out what each number does, aiming to turn all nine purple in as few turns as you can. Choosing the same number again flips its blocks back and still costs a turn. The patterns are dealt fresh every game, and every board can be solved in three turns. HARDER uses the numbers 1 to 9, with each block belonging to three numbers. The title keeps the best number of turns for each mode and the count of boards solved.

Controls: Use either controller. Push the stick left or right to pick a number and press a button to enter it, or press the number straight on the keypad; on the title, choose the normal game or HARDER.

ColecoVision version credited in the source to Claude (an AI made by Anthropic) for Amy Studio, in Amy, the language by Amy Bienvenu, 2026: a reimagined adaptation of the published rules. From COMPUTE!'s Gazette, December 1983: original Commodore 64 program by Andy VanDuyne. This is a modern homebrew adaptation, not a commercial Coleco release.