Try to implement perpixel alpha blending in C# and you'll see why there are no many games written in .net. The answer is - because there are many winapi functions which doesn't have corresponding .net methods. These functions are in most cases so-called low level, such as WINAPI UpdateLayeredWindow function. So, the only way to implement pp alpha blending is to call WINAPI function from C# but does it make any sense? Isn't it better to write the game in C++ and use WINAPI functions directly?