The art is good, but it needs definitively more polish (vignette, bloom, gain -> overall post processing), then you could add a Background texture. A few particles -> light sparks, fog etc. A nice music track would be good, something Arcade like would fit in my opinion. In short you’ve to bring your game worlds a bit more to life. I can recommend this tutorial if you want to learn about this:
And here’s a devlog by Blackthornprod that tells you about the almost same:
It would be very nice if you can play and rate my game too!