The sound was way too loud - this was caused by every enemy on the map firing at once at the start. Once I had taken out a bunch of enemies the sounds weren't actually that loud. You could fix this by just having enemies not attack unless they're within range of the player.
There was no feedback when you got hit which made it hard to tell if I had dodged the bombs in particular. I had to keep looking at the shield and health.
The UI was confusing - I'm not sure what the text in the upper left was for.
The gameplay was alright, but more feedback on when you and the enemies are taking damage would go a long way to making it feel better.
I noticed a few typos and grammar errors in the intro, and the font was hard to read. I'd recommend a different font for story text, preferably one with lowercase and uppercase characters.