This is the best I can do for now
A good use of the theme and a simple but fun game. I found moving the player to be difficult, there's noticeable pause between pushing in a direction and heading there. As well, the background seems to move at the same time to a degree which doesn't help to give a sense of responsiveness
Auto-fire is appreciated! There's no reason to ever stop shooting, so it's a benefit that the player doesn't need to hold down a button to do so. The random change to how the ship fires keeps things interesting but, since it's unpredictable as far as I can tell, doesn't change up the core mechanic of facing at the block you want to destroy most.
Most of the challenge (for me at least) is remembering which ship colour destroys which enemy colour. I think it's better this way than to have the red ship destroying red blocks, but it would be nice to have the information onscreen, perhaps using arrows in the section which shows which colour your ship presently is. (That display as it is feels a bit redundant since your ship itself is also changing colour.)
It might also be interesting if the ship didn't take damage from certain colours as a certain colour. For example red blocks won't cause a game over if the player's ship is red when they collide. It might also not be interesting, just a random thought. :)