Wierd
Worked for me fine on Newgrounds. As for the game itself, I personally found it a bit boring, though nice to look at. The upgrades need some work. The cannon upgrade didn't seem to do anything, enemies didn't seem to die any faster. And the add-on upgrade didn't seem to have any effect past the first one either, and considering the price, it doesn't seem worth touching. Also, the last boss bugged out for me too and just hung around doing nothing.
And on the subject of bosses, I hate bosses in games that have a huge pool of health and give no visible indication as to how much health they have left (or, indeed, if you're even damaging it) If they had something as simple as a health bar somewhere, of some sort, it would be worth an extra 2/10 for me.