Hey! I played again some more today. I played for about 3 times. Not much, but I think it was good enough to check some things.
The problem with the lives and portal seens to be gone, and the ajustment of the spawning of the ships fixed the problem that I had of being shot when I was trying to orienting myself just fine. I also didn't had problems with the game freezing.
For me it looks perfect now. Good job! :3