Reading online about how to develop for smartphones or tablets, there are about a dozen recommended mobile games development tools. While Unity 3D seems to get the most press, and GameMaker Studio gets mentioned often for ease-of-use, there are many new entries including Monogame - an open source implementation of the XNA 4 API. Cocos2d is also often mentioned. You can also find large lists of game engines on Wikipedia here and at MobileGameEngines.
Microsoft’s C# XNA developer tool – which no longer is being worked on at Microsoft – had many indie Xbox developer fans. Will this tool lead to an increase in the number of games on Windows 8 phones? Time will tell as some developers port their games from XNA (as in the video below).









