Some tips
The graphics are pretty good and so is ship movement but it's the little things that need some tweaking.
1. Being able to shoot faster. Not sure if higher levels offer higher rate of fire because they rarely showed up. But in the beginning that rate of fire is just too slow to kill any good amount of enemies.
2. More frequent power ups.
3. Not losing all power ups when you die. This is can change if you make the power ups more frequent.
Oh and I noticed that you become an ultimate weapon when you die and come back still flashing. You can kill anything you run into while that's happening. Worked with the first boss. Might want to fix that.