PSP games use a format called ISO. Compressed versions often convert the ISO to CSO (Compressed ISO) with a very high compression level (Level 9). The intro movies and cutscenes become pixelated or laggy.
If you cannot get the 100MB version working, here are better alternatives that require the same or less storage: naruto ultimate ninja impact highly compressed 100mb
Emulation (if you own the game legally)
Compression tips (for your own legal backup) PSP games use a format called ISO
When a file is compressed from 1.1GB down to 100MB, it isn't magic; it's science. Here is what typically happens: Emulation (if you own the game legally)
A: Usually, no. The compressed version strips the Ad-hoc connection files to save space. You will need the full 1.1GB ISO for co-op.