From FS Games:
Based on Defender, one of the best arcade games of all time, Planet Defence is now available for the iPhone and Touch.
Planet Defence is a fast-paced horizontal shoot'em-up featuring Tilt or Touch control to maneuver your space ship.
Defend the planet by protecting the humans that roam on the planet surface. Green aliens skim the planet surface and pick up humans, when they reach the top of the screen they mutate and the human they carry is lost. When there are no more humans left the planet explodes. New humans are dropped off every fifth level and the planet is restored. How many levels can you survive?
* Retro graphics - choose to play using classic arcade sprites * Online scoreboard - your existing scores can be automatically added to the online leaderboard, or you can choose to keep them private * Improved ship control - your ship is more responsive and closer to the original arcade in feel * Improved planet destruction - it is now much more like the original arcade * Improved enemy shot AI - enemy shots now try and predict your movement * Improved enemy movement AI - closer to the original arcade feel * Improved hit detection for ship and enemies alike