Hii, thanks for the comment! I just wanted to mention Kutaka Niwatari isn't featured in the game, I'm assuming you're talking about Shizuha Aki? I haven't really seen much content about her so I chose to give more of a highlight to the other bosses.
This game was more or less made to suit people that already play Touhou, so I didn't include any tutorial to learn how to play the game and assume the player already has experience with Touhou-like games. But thank you for pointing it out