Wow, this is a lot of game for just nine days of work!
The art style is super charming and really well made, especially the cutscene art and the main character's sprite -- my compliments to whoever drew that run animation, they did a really great job conveying the character's motion. The inconsistency of art styles between the varying assets was a little jarring, but given that this is a jam entry that's to be expected, and I don't think it detracted from the game at all. The music and sound effects are minimal but also very good, and I think they do a good job of reinforcing the atmosphere I think you were aiming for.
Like others, I ran into a bit of slowdown here and there, I'm guessing due to particle effects. And I found the controls a bit frustrating, although this could just be the old-timer in me coming out (I don't personally care for using the mouse to attack, I'd rather have a button to attack on the keyboard and attack in whatever direction I'm facing, a la Zelda).
Overall, y'all did a fantastic job on this! It's very creative and I can tell you put a lot of love into it!