Its worth it and the story ties in with the events of the original FF7, Remake and Rebirth.
You'll get more info on Zack - a character referenced in the original FF7 and the remake games.
More past information about Cloud, Tifa and Aerith - even Sephiroth.
The game is more action oriented than the original FF7, closer to Remake games.
I played it on the PSP years ago and imo one of the best PSP games. I got it on Steam and planning to play it in the future once I'm done with my playthrough of FFVII Remake Intergrade which I'm planning to do soon first.