A required .DLL file, D3D8.DLL, was not found.
If you're getting this error dialog, then you haven't got Microsoft DirectX 8 installed on your machine.
The game proper comes with DX8 on the disk, but the demo doesn't have DX8 buddled with it!.
But you can download it from the Microsoft site, here.
Will the game run on a Voodoo2?
Reports say no - we're trying to find out for sure.