Rollerdrome

For this achievement, you have to finish the normal Campaign before you unlock the Out for Blood Campaign (which is just normal campaign with all the enemies from the start and only 3 challenges per level instead of 10).

The quickest way to get this is to Settings > Assists > No Challenges Required > YES (While you're there, turn on Invincibility, Infinite Ammo, Infinite Reflex Time, and Easy Slug Shots. These will all make killing enemies simple.)

This will make it so the Final level is available in the "normal" Campaign.

Now go to the campaign and scroll down to the fourth (bottom) block which is labeled FINAL (should be the 11th level called Matterhorn Stadium) and start it. Kill all enemies as quickly as possible in phase 1 then kill the boss in phase 2.

Now the Out for Blood Campaign should be unlocked. Go into the first level and kill all enemies as fast as possible.

Achievement Unlocked!