Won't talk about it yet. I'm gonna say that regarding cartridges, there are at least four companies I'm aware of currently involved in the business (as in releasing Mega Drive games in the present), so there's that.
If you decide to go with a physical release, I'd like to see a bit more substance. Some kind of a story, preferably with an opening, cutscenes and an ending, and maybe more gameplay modes. I know that what you've shown so far is a work in progress, but I feel that releasing games on cartridges has become accessible enough for developers to become a bit... lazy, I guess?
What I mean by that is, the game has to be good enough to warrant a cartridge release, and I feel that's not always the case with some of the titles I've seen. I'd like to see more cartridge releases, of course, but I'd like them to be quality, fully developed games, too.