Develop prototype of computer game

We are working on developing a prototype for a computer game which will run on tablet computers running on Android platform. The prototype will be used to test the concept, develop game levels, tune up the complexity of the game etc. We have developed game concept and main graphics elements (look and feel) and now looking for experienced Android developers to assist in developing the code of the prototype. Prior to sending the requirements we need the candidate to sign the Non-Disclosure Agreement. Upon receiving signed the NDA we'll send detailed requirements and begin discussing rates, estimate, stages, deliverables, development process, controls etc. When sending a quote please include as many relevant examples of your work (game development on Android platform) as possible.