I liked the music and sound effects. Controls were simple and the main menu screen was very easy to understand. I didn't encounter any bugs.
Suggested improvements and observations:
Create a screen size option -- the default screen size is really small.
Player ship should be able to touch the very top of the screen (or at least make it clear that there is a boundary there). For example, I could dodge lasers on the bottom of the screen by flying under them, but it's impossible to dodge lasers on the very top of the screen by flying over them.
The first level is very tedious. It took me about 10 tries to beat it and my successful run took 147 seconds. That's a long time to be shooting down repetitive enemies without getting any power-ups or rewards in the actual level.