Nice demo! I played the web version. I liked the progress bar at the bottom of the screen. There was a good variety of enemy movements and spawn locations.
Obviously there are a lot of different creative decisions you can make when figuring out what to do next for future versions, but the core shmup experience is definitely there.
Although the keys can be re-mapped, I would suggest using arrow keys or WASD to move and space bar to fire. S, Q, D, F doesn't make much sense as a control scheme on an American keyboard.
It seemed like some of those buttons activated different powers, but I honestly couldn't tell what any of them did, so I just stuck with the default weapon.
Good job getting your demo out (two days early!)