All Monsters:
Enter the options screen while at the Soulin Monster ranch and highlight the "Buy Monster"
selection. Then, press R2, R1, L2, L1, R1, R2, L1, L2(2).

All Items:
At the options screen, press R2, L1, R1, L2, R2, L1, R1, L2(2).

Ending:
At the title screen, press L2, R1, L1, R2, L2, R1, L1, R2(2).