This trophy requires you to hit each TYPE of enemy with the pick, including bosses (except the Marian II Plant, the Helicopter, and Tank).
Checklist:
-Williams
-Linda
-Abobo
-Skullmagaddon (Stage 2 bossfight)
-Hoverbizzle (this one can be annoying, but either the regular or explosive one will work)
-Ichisumi
-Mecha Biker (Stage 4 bossfight. Make sure to carry the pick throughout the stage, even the airlock areas (again, Spin-Kicks work wonders). Just be careful when it gets knocked out of your hands to pick it back up safely.Once at the bossfight occurs, don't worry if the pick is knocked out of your hand. Leave it there until Mecha Biker is off his bike, line up a shot, and nail him with it. Watch out for his slides or he'll go right under it.)
-Shun
-Roxy
-Jiang Shi
-Boa Boshi (At the beginning of stage 10, there is a pick righ before the first encounter with him.)