It's good that working on your game enhanced your pixel art skills, and I hope you had fun participating, but part of the point of a jam is learning to manage your time well. Unfortunately, it sounds like perfectionism and ambition got in the way of efficiency, and the whole project got stuck as a result. I understand wanting to put out the highest quality game you can, but 10+ maps at 150x150 is a huge workload for one person, especially if you're constantly going back to rework assets.
I hope that you join us again for any future jams, and that you keep in mind that it's more about creating an early alpha of a game, rather than a fully finished product. It's great to see someone dedicated to their project, though, and I'm glad you took this opportunity to learn and create.