Generally considered to be the black sheep of the franchise, Phantasy Star III is definitely an odd duck in many ways. For starters, it does not take place in the Algo system at all; in fact, its ties to the previous games are fairly scarce and only made clear in the later hours of the game. Its gameplay also suffers because of a rushed production schedule that results in uneven difficulty and some underdeveloped new mechanics. The presentation also takes a hit, with minimal animation compared to its predecessors and music and sound effects that range from bland to downright annoying.
Still, in spite of its flaws and its rough presentation, Phantasy Star III has enough merits to make it worth checking out. For one thing, it's one of the earliest JRPGs to introduce a generational system. The story branches off into very different directions at two different points depending on the player's choices, giving a grand total of seven different playable scenarios in the game and four possible endings (though two of them end up being very similar...). It also has a rather unique setting even among the mixture of fantastic and science fiction elements the franchise became known for, as you will see once we dig into it further.
I intend to play through all seven stories during this playthrough.
A better explanation of the tech system in the game