The NVidia TNT2 is not recommended as it tends to be unstable under the load MOSES puts on it. Most manufacturers fail to install a proper cooling system, and under load the card tends to overheat and lock the machine.

Finally, if the water or ground appear to be moving in directions that don't correspond to the translations or rotations being applied, it is due to a lack of precision in your 3D video card. Some of the low end cards tend to use lower precision in their texture calculations; you may be able to increase the precision in the driver settings, but that is dependent on the video card. If the texture motion is too distracting, you can remove the files images/ocean.tga and images/ground.tga and the program will render using solid colors.