I love it! I could play it for hours non stop and I think your idea would be great for long rides or for a mobile game. I liked how your sounds work but you have to fix some stuff.
First game I played was against the dragon. I think a mere human without any upgrades can't beat it. Upgrades could be better too. Some of them are very unforgiving, some of them are straight up overpowered. They need some balancing. And after you defeat an enemy every projectile should be destroyed, Player can still be killed after the win and thus can't pick up upgrades.
But I liked it. I can't wait to see more!