Think like a code detective

The secret code has 4 pegs. Each guess gets pins: a filled pin means right colour in the right place, a hollow pin means the colour is in the code but somewhere else. Using those clues, players rule out possibilities until they find the code, within 10 tries. Easy uses 4 colours, medium 6 colours, and hard 6 colours with repeats. In friend mode, players take turns setting the code on a hidden screen; whoever cracks it in fewer tries wins.