Thanks for your interest in the project, but unfortunately I don't plan any updates. I consider that the project is finished and will only update it if I need to fix bugs/secret ways or for difficulty balancing.
My original goal was to include as much features as possible into a 32 kB cartridge (the smallest available) and since it is 99% full, I consider that the project is done and I prefer working on other fully original projects.
As a side note, if you want to generate your own ROM with your levels, the code is available in another comment on this page (but I didn't plan to share it so it may be hard to use)