Here are 2 games with different styles, Monster Truck Hero (PC/Mac) and No, Human (iPhone). Both games are Unity based.

The first video, "No, Human" game play trailer:

Monster Truck Hero, model made with Blender and Gimp

... This game purely built on open source software available in the market and works seamlessly in both MAC and Windows Environment.

http://www.youtube.com/watch?v=4d1q8CsDE60

Links: