I love it! A couple suggestions:
1. Enemies spawn suddenly. To telegraph this, add an indicator, such as a red exclamation mark, before they spawn. Also, a “fade in” animation for the enemies before they start moving would be good. Or, you could have them fall down from off-screen!
2. Menus are a bit confusing - maybe reorganize them.
I don’t mean to presume, and I don’t know how attached you are to the current music, but if you’re interested, I’m a composer-in-training myself and would be willing to make some for you, if you like. Contact me at lucasjonesgamedesign@gmail.com if you’re interested.