this one is a lot of fun! and congrats on your first jam! :D i like the silken shot and the thunderweb attacks--they felt varied and interesting. i wasn't quite sure what the snaring web did, though. the name makes me think it slows enemies down, but if it did that it wasn't very noticeable (but then again, i only got one level in that weapon i think).
some more movement patterns for the enemies would help this game a lot. when all of them follow you like this, it's easy to circle around and group them together. it would also be good to add an exit game option, in case you need to stop for something.
all that said, this is a great game (especially for a jam and ESPECIALLY for your first)! the boss caught me off guard, and was really fun! i hadn't gotten any extra lives as an upgrade because i wasn't losing too many, but that boss got me close to dead D: managed to pull off the kill though!