It is indeed also on Itch. I'm planning to release both, along with a physical cartridge at some point. It's a real NES game, so a ROM is included. (No DRM, of course. I'm not even sure how you would achieve DRM on a ROM chip.) I test on an Everdrive N8 Pro. It's a big game, so simpler flashcarts tend to not be able to run it.

https://zeta0134.itch.io/tactus

Aye, the inspiration is not subtle. Technically it is the latest entry in the "rhythm-based roguelike" genre... which to my knowledge mostly includes CotN and its sequel, Cadence of Hyrule. Both are excellent, and I recommend them highly. Of course I'm unaffiliated, so this is more of a spiritual successor (... demake?) and is its own thing in terms of IP.