Sharpex2D allows you to create beautiful 2D games under .NET for Windows and Mono compatible systems. This engine is completly open source and free to use, even for comercial projects. It's written in C# and supports the following graphic frameworks.
There are also different types of handling input. The supported devices are listed below.
Checkout the wiki, and get a quick overview of how to use Sharpex2D in your game.
You can download the engine via nuget (https://www.nuget.org/profiles/ThuCommix/). For additional info visit http://sharpex2d.de/ . The source code can be found here: https://github.com/ThuCommix/Sharpex2D .