Wow this is the second game i rated 5/5 on everything in the jam. The art on this game is just fantastic. I really dig the 1-bit old black&white mac style artwork. It kinda reminded me of the old classic from 1990 "Immortal" with those faboulous 8-bit musics and all.
Other than the music the boss design is also top notch quality. You got the different attack patterns, phases and all that. Boss battles are a great deal of fun and very engaging.
I personally think that this is one of the games which uses the theme of the jam in the best way. It is definitely brilliant. Like you didn't use it gameplay wise but you used it as a plot device for the story of the game. It was a great example of out of the box thinking.
Man i get jealous that i cannot make games like these but i also learn a lot of things from them and they fire me up to make better games, to improve myself further.
I love every aspect of this game. Congrats to the team and good luck on your future projects.
PS: I also was working on a game where you fight against a series of dragons but that would be a 3D game. I later scrapped that idea to make a game which also fits the subject of Samurai Jam