I tried for quite a while but the final phase is too much for me. The best I could do was destroying three of the four crystals. There's so much stuff happening all the time!
I really like it! The music is great and it controls well. It's satisfying to learn how to deal with the moving platforms and to take advantage of the Last Stand mechanic. I also appreciate that you get a breather from the boss's projectiles in phase 3. and... WAIT. YOU CAN SHOOT STRAIGHT UP?!?! Okay give me a moment here...
... alright, I'm back. Still couldn't do it, but I got close once!