Used to bash out Metal Gear Solid 3 speedruns nightly for a while at university. On European Extreme I think I managed to get under the two hour mark with 0 kills and 0 times discovered. The favourite run I ever did was a Very Easy 1 hour 35m with 0 kills, 0 times discovered, 0 deaths, 0 damage taken, 0 food eaten run.

The difficult parts are the bosses.