How to find unlock items

[LunaMoo]

As with every cheat, you need to understand how game works as it's never exactly same and then do whatever you want to make it work differently or patch the table it writes/reads from, but since games in modern times are allocating memory dynamically and that counts for like half of PSP library, just patching tables might corrupt game memory and cause anything from crashes to permanent save data corruption.

Most games from same studio or based on same engine will share similarities, but proper cheating is really all about learning and low level programming. You typically start by searching some variable value you can affect in game, then check what game functions are using it and you read the compiled game code in assembly.