You joke, but given the man power, you could do crysis in Blitz
Not unless you wrote a software renderer :). Really, there's no way a DirectX 7 engine can match the quality of a DirectX 9/10 engine - without the advanced shader effects, it really wouldn't be Crysis any more. Not to mention a DirectX 7 version of Crysis, even without pixel shaders, would probably run much slower even on the top hardware, since a lack of vertex shaders would make it impossible to use hardware acceleration for animations, etc.