Hello. Good job so far. I have the following critique:
The aesthetics are extremely derivative. Of course I can't blame you for emulating your favourite games, but it's a bit too much for me when I see something that wants to be Progear and a host of general capcom and cave games so badly, artistically. Down to the busty females for pilots, I just don't see the point of you know, that sort of artistic incest. The concept could stand to be a lot different, the art direction not as tired as that, the sources of inspiration not that clear (In the Hunt, Metal Slug, Progear) and generally, more YOU than '90's coin op'.
Art-wise that's my biggest concern. It's too late to change now, I know, but I just had to say it.
Code-wise:
When stuff blows up on the air, the explosion still carrying horisontal velocity is okay, but not on the ground, it seems as if the explosion is travelling.
Bullet patterns are aimed streams and some very basic carpets, we've seen all that before a million times since 1985 to 1995. Now for most non-shooter fans, that'd be fine. For people that actively play and call themselves fans of shmups, that sort of barrage simply is boring and one-trick. I suggest you break out the stops and put creative, colorful and challenging patterns on-screen. Perhaps on next levels.
I see no point at attacks from the rear in these games, and not many good ones have them in. Take a cue from them.
Fast bullets. This is a bit of a matter of preference, and only ground units use them which can be dispatched easily, and they're not aimed at you, but still, fast bullets for me, spoil a shooter mostly. Just a thought.
The ship doesn't control quite cleanly. Does it move one pixel at a time? If not, it should, and it should be as responsive as possible. There's also some flicker and stuff going on, is the engine suffering from too much on screen? That would be needing of sorting. It just doesn't feel smooth enough at the moment.
The sideweapon is not very useful at this time.
Music-wise:
I find that old-style amiga dance beat type of music very boring, and not fitting to this game. Also, sound-effects I guess are placeholders? You're missing a lot that will make the action very much more happening.
Congrats on having something in your hands that's better than most amateurs do in terms of presentation. But the gameplay needs a lot, still.