Develop an iPhone Game - Art assets provided

We are looking for a quick and cheap developer to make a game that features our characters (6 in total) all sliding down a hill from the top of the screen towards the bottom (sort of like a reverse Mega Jump). Each character would come with his own object to slide on and his own background, and they would be purchasable with coins collected in the game, or all could be unlocked for 99c. The game should contain: -A Splash Screen -A Main Menu Screen with [Play], [High Scores] and [Share] buttons. -A Character Select Menu accessed after the [Play] Button is pressed, with One selectable character and 5 "locked" characters. -The Game itself, which would track how far you have traveled, allow you to collect coins and avoid obstacles, and end once you fall into a hole. -A Game Over Screen with [Play Again][Character Select]and [Share Score] buttons. -A High Scores List (Top 10) which appears AS the game over screen whenever you get a place on it. We will provide all art assets. For an idea of what the gameplay should be, look at the game "Critter Drifting" on the iTunes store (free download). We want it to be similar, but with additional functionality, including: -The ability to tilt forward or back in order to maneuver more effectively around obstacles. -Obstacles and Powerups that help or hinder your forward progress. -Pits or Traps that end the game. -A rare item that allows you to run over a pit one time without ending the game. Please include how long you think this should take and some links to previous games that you have developed.