Nugget is a 2D platformer game with a z-depth twist.
It was released in December 2012 for PC and Mac, and optionally included the full game editor NuggED. It holds the comically-specific title of "indiegames.com's #2 Free Platformer Game of 2012".
Unfortunately it is incompatible with recent MacOS (since they killed 32-bit apps) and runs poorly on recent Windows (game was made on XP) and is not available at this time. Sorry!
Nugget is by R. Touk featuring music by Kevin MacLeod