Avoid getting stuck
Try to run up the side of a bank that is meant to be a barrier. You may get stuck in a bush or behind some rubble or rocks. Rapidly tap X to jump while moving your soldier in side-to-side and forward motions towards the bottom of the bank. You will eventually find a spot where you can jump and get back on level ground. By doing this, you will not have to start over at your last checkpoint or restart the level to get free.
Getting second flamethrowers
In the second to last level in the game, where the tank goes across the track where you are on a ledge, go to the edge but do not fall. The person holding the flamethrower should die then pick it up. Note: The second time will not work.