Here is a quick proof of concept level I made for a iPad game I am designing at the moment. It's a kids game, hence the bright colours. This is a test level, it won't be used.
I made it largely to prove how easily it could be done and to what level I might expect the result to be. The whole level took me a couple of hours including textures.
I set myself the goal of making a quick and nasty iPad level to get my head straight about what type of game I was designing. I won't go into the details, but it really helped me decide that the game won't from the first person perspective.
Click here to run the level (use standard wsad first person shooter keys). The lighting isn't very good because I'm only using the free version of unity which desn't support anything better (fair enough).