Great game. A bit too "grindy" when it comes to powering up. Should be less upgrades that have more impact instead of lots of upgrades that have very little individual impact. Also auto fire should just be on by default with a toggle to turn it off. Just my opinion though.
Side note: Been a while since a saw a shadow boss, very retro, and very cool.
When certain pieces are on the edges of the screen you cant spin them. Controls are a tiny bit sluggish too. Not bad overall, just needs some more polish.