I was hoping you would update this and you actually did.
Looks better with the models, trails, and the muzzle flashes of the guns.

Although not needed to fix, there was a problem with screen locking (or was it mouse locking?) After clicking offscreen, the screen locking disengages and whenever I pressed spacebar, the page scrolls down. A refresh of the page fixes that easily, but I thought you'd like to know.

This was pretty fun!
Even using trackpad, I managed to navigate without a lot of worry.
Fun, not super hard to understand, and compact for what it is.
I only have a few suggestions:
*While I understand it would probably defeat the point of them, I would enjoy being able to destroy the chaser planes
*Add a bit more variety in the layout? Perhaps (if you ever decide to expand on this, which by the way, would LOVE) you could make a 2-to-4 world set (Worlds can be just about as long as this was, maybe even shorter. It was pretty enjoyable for its length) with some unique enemies per world?
*I like like the music, but it feels just a little too repetitive (getting Super Tux vibes, but it doesn't feel as charming).

Loved the skins, the enemies, and the minimalist style (especially since it held true to providing a lot of info with minor changes in design)