Seems like the sort of beloved project with solo maintainer that could go open source in the future. I wonder if there is a common approach to allow this to happen like open source foundation working with him plus community fundraising. I'd support such an effort with 10x the amount I paid for the product.
A very similar open source project, Tic-80[0], already exists. It has tools for sprite generation and music creation. It also supports Lua, in addition to Fennel (natively), JS, Wren, and Moonscript.
