What a wild ride, but in the end I got something actually playable! Definitely rough around the edges, but generally happy with the results. Here's my LD38 Compo game: The Blockings

The Blocklings are on a distant planet, and they must journey from planet to planet until they reach home. You are their guide, placing blocks on each blocky world to guide these lovable but helpless creatures from the entrance portal to the exit portal. But be careful! Each of the 9 planet is fraught with challenge and danger, and one wrongly placed block could cause your blocklings a fall to their death.

• 9 Increasingly difficult puzzles to solve
• Sharp retro semi-isometric graphics
• Soothing and enchanting music
• Developed with only free software