It seems like a question that pops up on a near-daily basis on our forums is "How do I get started to make my own game?" Well, if my Twitter feed is any indication, iOS developers can't get enough of Unity and, as this video illustrates, you can have a totally functional prototype of a basic game using the Unity development environment in under an hour:
What's even cooler, is that all the tools shown in the video are totally free to download, and there's even a fully-functional 30 day trial of the "pro" licenses. You don't even need to know how to build 3D models, as the Unity Asset Store has tons available, both for free and for reasonably cheap licensing fees.
If game development is something you're interested in, but don't really know where to start, give this video a watch. A lot of stuff might initially go over your head, but that's OK, there's no shortage of Unity tutorials online and you really can't go wrong with all the software being free-- The only cost to you is your time, and really, if you're learning something, that's not much of a "cost" at all.