In order to get these character achievements, you will have to play the game three times. Not to worry, the campaign is short and easy and you do not have to do every last level, just do the levels with the achievement names in them. You will have no problem getting these achievements and really no advice is needed because these are easy, just play the game on easy and you should get all these character achievements in under two hours. Remember, just take your time and take cover. Heal when needed because there are only one or two levels where the enemy can actually take your base. Just shoot everyone you see, and if you can, run through the parts you can run through.