I like the concept of your game, however it seems a bit sluggish on my Nexus 7, also I find it hard to get the Fire projectile to go the direction I want to fire it in.
Thank you for giving it a try! I have received this feedback a little earlier today and since then I tweaked the graphics in the hopes that it will make a difference. The update should be published by tomorrow.
As for controlling the direction of the ammo, I am not sure yet how this is happening. I will need to find someone with a Nexus 7 and experience this behavior for myself because I have tested this in the worst possible environment (Android simulator) and I was ok in there.
Also, starting at level 7 a lot more fun stuff will go down, hang in there!