This project is intended for our collection of easy ‘make it in an afternoon’ soldering kits.
It will be a small board with 9 dual colour LEDs arranged in the usual Tic-Tac-Toe pattern. There will be nine small buttons arranged in the same way below the LEDs. There will be an additional LED to indicate whose turn is next. A long press on the centre button will clear the screen for a new game. A second long press will select one of three modes. Mode 1 will be one human player against the machine, human goes first, mode 2 will be one human player against the machine, machine goes first and mode 3 will be two human players.
So it should be fun to build and fun to play afterwards.