It's pretty easy actually. Just kick the bosses all the time, and remenber to pick up all the spears (down) If you dont have 46 kills after to second boss, you have to play level two again to get the hard badge. You see, you have to kill the boss with out die. (that is the glincth, not the "dosen't count kick kills" that is wroten in the badge info) To kill the last boss you have to have at least 2 life left!
 "Achilles"){kind=icon}
 "Hero's Arms"){kind=icon}