This is unavoidable achievement if you finish the game. The game is rather simple to beat; one of the important hints to beating this game easily is to be a position that isn't going to be getting tackled much, so as to not get injured. If you get any major injuries (season ending...) your game ends and you have to start that game over again. This is incredibly frustrating in one game, which takes place in a prison yard, with a no holds barred style format.
My best tip, play it safe. Don't get cocky and you will be able to be the game quickly. Let the time run off the clock whenever possible.