Quite a fun and polished entry!
Gameplay-wise, I think, having a currency system or something that prevents me from spamming all the guns would make it more strategic.
Also, since you have a variety of weapons with different abilities, having in-game descriptions would be nice because when I started playing, I had already forgotten everything. And maybe the enemies could have different weaknesses but that’s probably outside of the scope of the jam.
I liked that the enemies got smaller so you have to place towers of all sizes.
Nicely done!