RedAndCosmoteer
The crash, I reckon might be from the Large Turrets, because the Large Turrets are a pain.
A answer: I have a little bit of experience spriting from my HTML games which never got published. They are very crappy, but I picked up some skills and know-how from them. And also, I practiced.
This was my first Cosmoteer Sprite:
Not bad, but not good 😛