iOS uses Objective C. There are some other ways, but essentially you need a Mac and xCode to build for it.
Android is primarily Java. Again, there are other ways, but for the most part you use Eclipse + Android SDK
MS actually seems to be making more roads than other in making it easier to build apps for their platform (probably because theryre desperate for developers).
You can obviously use Visual Studio and the WP SDK, but there seems to be this new thing I havent played with yet: Windows Phone App Studio | Microsoft
Something we're looking to play with at work is: https://www.touchdevelop.com/
Do you want to learn how to code? Or do you want to make an app without coding?
Learn how to code. Easier it will be C# or Java.
Without coding well MSFT makes a lot of resources available like app studio. People have been creating basic apps with App studio. However, there are other sites for iOS and they are better than app studio
Check out Unity. Visual Programming might be the way for you to go. Easiest to learn. However, you might have to buy new tools every two years.
But my opinion is that you should be focusing more on the art side when it comes to games, as the art and gameplay matter more than what you made it with.
If you are coming from a web development background I would agree, moving into WP development does have a learning curve, the feedback loop for mobile environments is a lot more cumbersome than for web. For .NET programmers that have a background in WPF the transition looks to be much easier.
To the OP's original question game development is so different than business app development I would evaluate the difficulty of the platform for one type of development or the other.