During the mini-game The mercinaries, when you get up to the Nemesis, don't run away. Instead, fight Nemesis to get an extra 20 seconds. If you are playing through the game, you should encounter Nemesis at the crashed bus and becaused he has changed, ypu will get an extra 2 minutes. This is best done with Mikhail because he has a rocket launcher. Don't do this with Nicholai!