Tales of the World: Radiant Mythology is one of the greatest RPG's for the PSP.
Now let me review some of the game's aspects:
Gameplay: Using Namco's Flex-Range Linear Motion Battle System, this game even puts Final Fantasy's Turn-based bull%$^@ into shame. The only bad thing about the battle system is that your allies don't know how to cancel a spell.
Graphics: The graphics are great for a portable, but doesn't use any of the advanced capabilities of the PSP's graphics system such as bump-mapping and the like.
Sound: The sound seems pretty nice, although you won't be impressed by the voice acting if you seen videos of the Japanese version, and they unfortunately cut out the vocals of the opening sequence.
Overall: This game is worth more than it's priced. It's too bad that we didn't get the rest of the TotW series before Radiant mythology.