Codebreaker (itch) (Cyningstan)

This is a Tiny BASIC version of the classic code breaking game. The computer chooses a 4-digit number composed of the digits 1-6, and you have to try to guess it in ten attempts or fewer. The computer gives you clues: a black peg for each digit you guess correctly, and a white peg for each digit you guess but put in the wrong place.