Ignore many of the older 1-star reviews... Controls are GREAT as of version 1.2
I got this game after the update that fixed the controls, and although I had never played it when the controls were problematic, I can definitely say that (as of version 1.2) the controls are excellent (simple, consistent and very responsive). Nice to see a developer that is obviously reading the reviews and making an effort to make the game better.
As other reviewers have mentioned the graphics are very nicely done. Sound FX are also quite good. This is definitely one of the more polished games of the space-shooter genre that I have seen for the iphone. Seems like a really easy game to pickup and play while still having alot of variety to keep it interesting. Overall, I would rate this a must-have if you are fan of side-scrolling shooters (think something like a space version of Raiden, 1942, etc).