Is NES Puzzle Maker allowed?
Which emulator it runs in doesn't matter; it's about the hardware configuration of the ROM itself. It looks like NES Puzzle Maker using NROM, which is allowed in the competition!
Here are some rules specific to NROM to make it compatible with the Multi-Cart that we release at the end of this:
You will need to reach out to the NES Puzzle Maker creator (https://twitter.com/cppchriscpp) as see it the tool breaks any of those rules. It will not be an issue for entering the competition, but it will only be an issue with getting your game on the "Action 53"-style multi-cart (if we ever get one put out).
Good luck!
For the record, I'm not the original dev of Retro Puzzle Maker but I have put together a project in it (GRAVEYARD DUDE), and am currently working on a second, that involve heavily changing the code of the base and as such have been in pretty regular contact with Chris, the Retro Puzzle Maker dev to share code. Anyway, I can confirm that it conforms to the requirements. I've even managed to successfully add GRAVEYARD DUDE to a multicart (Super Mario Bros + Duck Hunt, basically the original multicart!) in a previous experiment developing multicart ROMs myself.
FYI: There was a big update to NES Puzzle Maker which improves what can be done with it. See the full update here: https://puzzle.nes.science/home
NOTE: As of 1.4.0 there is a special "flag" you need to set in order to make the ROM compatible with this competition. ROMs made with NES Puzzle Maker prior to 1.4 are compatible as well.