I used a code too, sorry don't remember which one :-(
Great start and here's my review
*** "Very unique game play, takes a bit to get used to the controls but offers power-ups and the fact that you run out of ammo adds to the game play so you can't just hold down the fire button. The graphics are very well done."
^^ Let me know if you want it posted in iTunes.
Suggestions:
iTunes:
Add something / anything about the next update, I know I am much more likely to purchase if I see an upcoming feature and something of a commitment from the developer.
Settings:
Include Settings to toggle sound and adjust movement speed as already suggested (my feeling is a player should never have to "get used to game controls", the game should adjust to the player).
Help screen:
When you first open it and then press the green arrow it lags a bit and if you press the button a second time it jumps to the 3rd panel and there is no back button. It would also help to put some type of page counter so I know I'm done. Could be as simple as " 1/5" or even some phony dots (although you should implement swipe if you use dots).
Game flow / timing:
It just seems off to me. Perhaps change it to allow the player to tap when he/she wants to continue not after a timed amount. The end of the game (which I experienced often ;-) ) takes way too long. I just f@#ked up but now I have to wait like a whole 6 seconds before I can play again! :-)
On-line scoring:
I've just got to know where my score of "70" sits in the world! :-D
These are just MY thoughts, by all means do with them what you will... :-)
Good luck in the store
CG