Cool game, I liked the idea of having an objective to protect on top of the existing idea in Vampire Survivors.
The art looks amazing,I don't know why you feel like it needs to be changed it's very appealing. The main thing imo is the balancing, it got a bit stale at the end, but I really like the idea.
I've made my own roguelike inspired by Vampire Survivors and it's playable on web. If you feel like it I'd love to hear your feedback on it at Plague Survival .