This was my first big homework in the University. It was made under a week in C and with SDL2. It had to be smaller then 1MB if zipped, with all the images, sources, and documentation. It works on Windows, and it (should) run on Mac too.
It has a limited map set, but with the built-in editor it can be expanded any time by the user. (Levels can be shared with a little trick.) The editor will only let you save if you solve the map beforhand, so you can’t save unsolvable maps. Also check if it has valid elements. (No option to escape from the level, enough box/goal and a player must be present on the screen)