For all secret items (including Langrisser and Alhazzard), try this. At the "Buy" word press left, up, down, right, left, select, right, up, left, down, right, select, circle.
Level Select
At the "Load" screen, highlight any of the scenarios (not the first one) and then press right, down, up, left, R1, square, start, select, triangle, circle.
Secret Items
At the "Buy" word press up, left, right, down, right, right, circle.
Test Mode
At the "Load" screen, highlight any of the scenarios (not the first one) and then press up, down, up, down, left, right, select, circle