The concept is there, but...
...it's somewhat flawed.
First, the major downside to this game (which is still rather fun) is that there is no pause button. Especially annoying during survival, when you need to do something. Next time, be sure to add one.
Second, the physics collision are horrible. I died many times because parts of enemies got stuck in my weapon (or even body, sometimes). It should really be worked on.
Third, the AI isn't too good. It just swarms at me. It's not really a good tactic because when they're too few, it's too easy to counter, and when they're not too few, it's nearly impossible to counter as they close in in a tomb-like crush. They sometimes also just fly off-screen, making it impossible to progress further, which is frustrating.
The controls are clunky too. The ships could be much more reactive.
On the bright side, the game concept is pretty good, the graphics are great, and I absolutely love that you made everything the AI uses available to the player. That is a HUGE plus. I especially love the two-sided weapons.
In the end, the game is pretty good, but could seriously be worked on. 6/10, 3/5.