I just didn't see the reason for the majority of experiments/scenes, just a few examples:
1. What is the reason for the frost bitten hands experiment? Except for the sadistic pleasure of the "doctors" other reason I cannot find. The purpose of the squadron 731 was to create chemical and biological weapons, so what did that have to do with it?
2. The death in the compression room - again, pointless.
3. The cat scene, which I am sure it was REAL, shows the pure sadism of the Japanese "scientists". But then again, as the scene was real, and the movie was made by Chinese, what is the difference between the producers of the movie who re-did this and the japs?
The film fails to explain these, and others.