I like the themeing(sp) and graphics a lot. I feel like this is game style is needed on SMS - a dragon themed shooter.
I was running it on mednafen/mednaffee 0.9.2, and the background scrolling speed would go slower when enemies were on screen, then quicken up when they were gone (not sure if thats intentional). Also when I would time out on the boss, the screen would start to scroll again with the wrong tiles on the background. During the multiple playthroughs, I never took damage, neither did the boss - not sure if this is just 'not working yet'.
As far as playability, it was hard to tell which weapon I currently had selected, and how exactly the weapon powering up system worked.
All in all I liked it.