There's a lot to like here. It seeks to be a love letter to the Genesis era and specifically Gaiden games, and it succeeds. The gameplay is pretty fun until you unlock enough movement that it becomes cumbersome and frustrating. The music is top notch.

Cheap hits, unavoidable enemies, then tediously re-do the whole section endlessly until you have every pixel memorised and can finally progress. It was bad design in the 80s and it's bad design now.

For the fans of Ninja Gaiden, as noted by pretty much everybody in existence. Platforming feels smooth, the game doesn't feel cheap, the progression is steady but rewarding, the story is okay, and the difficulty level seems pretty balanced. I never got overly frustrated to the point over some bullsheet that I wanted to rage quit.