does it half to be exe or can it be png
I think he is asking if a Pico-8 distributable cartridge (requires Pico-8 runtime) is suitable. In the same way an Atari game was limited by cartridge size but didn't need to worry about libraries that were built into the hardware Pico-8 (software) simulates a fantasy game platforms hardware and the distributions can be PNG files which look like cartridges. Its a cool system. So the question for you is if the game libraries that render the game need to be included in the floppy as is the case with traditional oldschool Dos games etc... or if a retro platform cartridge equivalent which only includes game assets, data and code qualifies.
Given the rules don't state it has to run as a Windows Executable etc... it seems to open this up as a possibility.