Good game but needs some tweaking, it's a bit too tough and frantic as it stands. 

I felt everything moved way too fast so I didn't feel in control. Ship left/right was too quick. Maybe make the sprites a bit smaller to make some room to dodge & so top to bottom movement of enemies give you more time to react. 

Need some feedback the enemies get hit rather than just disappear. Also some feed back that you are getting hit would help - not just the health bar. 

Some variety in the enemies or what they shoot would be good too - maybe that comes in later levels but I wasn't able to survive long enough to see those. 

Some progression to make the game a bit easier to start with would be good too.

I think a littlle more development could turn this into a great little space shooter.

Nice concept, but it's got problems.

-Movement speed is way too fast. Holding the movement keys makes you almost instantly zip across the screen!
- Killing enemies feels very meh. An explosion animation or some sound effects would help a lot.
- The player needs invincibility frames after being hit. If there's a string of bullets coming towards you, then it's really easy to die instantly.

These are pretty simple things to fix and if you do I think you'll have a solid game. Nice effort all the same. I can certainly see what you were going for :)