Quack is a puzzle game inspired by the Dr. Mario series of games, for the Commander X16 computer
You can download the game and play it online on the official X16 forums here: https://cx16forum.com/forum/viewtopic.php?t=6775
The sound code uses a fork of MooingLemur's zsmkit library, created by me. Graphics were created by AJenbo, many thanks to both of them.