Zombie Apocalypse Survivor achievement in Judgment

Here's a faster way I've found to do pickups

1. Start Chapter 3 of Kamuro of the Dead
2. Use grenades on the first three screens
3. On the fourth screen, the one with the flying monster, there's a barrel. Shoot the barrel and then use the grenade you pickup.
4. Exit the mini game.
5. Repeat.

You can do each run in about 30 to 40 seconds. When you start the chapter, just spam Y through the first screens, shoot the barrel on the fourth, use the last grenade and then quit. Should get it done in about a half hour or so.