This sounds really interesting! I'm not a programmer myself, but I recently learned about the history of handheld games through Lost in Cult's books on the topic, and it's really impressive to see what people can/could manage with hardware limitations.
I'm also a huge Metroid fan, so I would personally love to learn more about what aspects of the game's isolating atmosphere, and how the Metroidvania genre plays, impacted this prototype. All the best!