The last great Star Ocean game for sure. Maybe the only one, I wouldn't know. I never got around to the earlier ones.
SO1 wasn't actually released in NA until they created the PSP port in 2008. I got around to playing it a few years ago and it was quite enjoyable. Nothing ground breaking but about what you would for a brand new game in the 90's.
SO2 is where it really took off. SO2 is phenomenal. IMO one of the best RPG's ever as it allowed you to chose to play as the male or female main character. Regardless of whether you picked Rena or Claude, both were in the game and playable. It simply came down to which story line you went more in depth on and certain characters/equipment were only available on certain story lines.
SO3 is different. Story is much more in-depth and you went from a 4 member battle party to 3. It also introduced the concept of MP kills which some loved and some hated. With 4 difficulty modes and 300 battle trophies and countless post game dungeons, you could easily spend 500 hours on the game.
I couldn't get into SO4. I hate the boss battle concept of weak points where you essentially are kiting for 99% of the battle except for the 5 seconds the boss exposes its weak point. I may give it another shot this summer once I am done studying for the SPHR exam.
SO5 was a hot mess. Game had potential but the story was lacking and there was no depth. Big, beautiful cities that you couldn't do anything in. The 7 member battle system was just insane. Way too chaotic.