Jumper

Save this one till the second time through the game. It really isn't as bad as it sounds. An important little tip is that the good ol trick I used to beat F.E.A.R. without dying also works on this game. If you die, quickly turn off your xbox. After you get going again load up your save and continue and the achievement will still unlock.

Most of the game is very simply, but Sam Jackson and the very last boss in the trench coat can be quite tough. They both have a very strict pattern though, so simply find their beginning weak spot and then memorize where the following weak spots will be. Repeat the same combo over and over. Try to end your combos with a  attack, becuse that will knock them down so you can back up and get ready for your next combo. If you don't knock them down, they might catch you with an attack and then combo half your life away.