Swing
Pick Djunn as your person. On level 1 when you go into a bilding swwich to your energy hook. Befor you exit, at the back door throw your energy hook at the roof. It should stick if not charged. swing and jump on the roof. There are different items. This is hard, it may take more than one try.
Lots of weapons and ammunition
Enter KL987 NT465 0001 as a password at the inventory selection screen.
Full armor and doubled ammunition
Enter KN28F 9526K as a password at the inventory selection screen.