I'm a big fan of old school shooters, and your game does justice to the genre. The movement is very smooth and the fact that your weapon and melee can give you momentum is something I love in this kind of game. My biggest complaint would the lack of feedback when hitting an enemy, since there were many times I finished a level and though I was on a cooldown. Maybe showing the boss die (and a death animation) before changing level would of been nice.
But I will definitely keep an eye out if you continue this project.