I believe there are bindings for SDL and OpenGL so it's certainly doable, also although Vala's syntax is modeled after C# it compiles to first to C and then native code which means it performs better. There's also garbage collecting through ref counting iirc.
Other alternatives would be Google's Go which is fully garbage collected but compiles to native code and has strong language support for concurrency. There's SDL, OpenGL, GLFW bindings for it last time I checked but given that it's relatively new and still in development I wouldn't suggest starting a serious project in it just yet.
True, if we don't count flash games then C++ is most likely still the number one language in which games are written and it's not as if RAII is a unknown concept in C++ game programming.
So the SimS 3 is written in mono? Now that explains the abysmal performance for the medium-to-low graphical quality!
God damn is there a whole mess of incredibly thick stupid in this thread.