These are considered native:
* Dreadnought
* Far Cry
* Half-Life 2 (Automatically retrieved through Steam)
* Unreal Tournament 2004
The main exe is 64bit. In FarCry, there is no noticeable speed increase, but they have improved the texture quality without dropping the performance, which is in fact a performance enhancement.
Almost all the other games will run in Windows x64 environment in WOW64 mode. They are compatible, but doesn't run natively in 64bit. All the games I have installed right now are compatible with Vista x64.
