Well, I beat it...
Can't say it was easy or fair, but I beat it =P
I liked the graphics of the boss and the player. The music was kinda cool, it reminded me a bit of maybe Ghosts 'n Goblins or something like that (if I'm remembering correctly). The white lines pissed me off, lol. They definitely needed some sort of indicator to tell you where they were falling. They did so much damage and there did not seem to be a pattern to them at all. The same as the spikes at the start, it was impossible to make it through that section without getting hit, because you either positioned yourself to avoid the spikes or you avoided the bullets, it was an either/or situation. The spikes should've shook for a bit of time before they fell, to let you know where it was safe to stand next. Also, the bullets really should've been getting destroyed when they hit the boss, it felt like I was throwing wads of paper at him (which, considering his health and the difficulty of staying alive as the player, I guess I was).
It was fun, in that frustrating kind of way, but (as I'm sure you're aware) it definitely needs a ton of polish. The biggest thing is fairness. Did I die because I made a mistake? Or did I die because the game rolled a random number. A lot of the deaths in this game felt very much like the latter. If that were fixed (i.e. there was a pattern or at the very least an indicator of where things where going to fall) it would've went a long way towards making this boss fight much more fun. The platforming itself was smooth and I liked the forgiving nature of the platform hitboxes. I didn't once feel like I died unfairly because of a fall when jumping between platforms, which was good! Overall definitely rough around the edges, but I can see where you were going with it =)