Steps for acheaving:

1. Get about 100 ammo
2. Go to hospital
3. Locate area with Mixedman enemy
4. Enter battle with a weapon without burst
5. Kill all the balls from the mixed man untill taget count is 90
6. Let maximum number of balls on the screan
7. Kill one of them, and when another is bouncing kill it

   Note:When the mixedman fires one more, all of them will expand to a larger size.

8. Now kill all the balls

   Note:Each doublesize ball will drop an ammo 30

9. Kill the Mixedman

   Note:If it droped an item, the item is upgraded

The battle is good for bonus points and experance and any ammo droped