These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The case for this may come about because of the order in which people play the games. If it's the first game in the tetraology that one plays, the main story isn't known and this game's universe is isolated enough to be a good starting point with the rest of the games coming in at a later date. But for those who played the other games first... yeah.
It also was not developed by the original people as I, II, and IV. Combine with the story separated from the rest of the rest of the universe and the radically different artstyle, it looks almost like it's not even a Phantasy Star game.
Game Breaker: Sari is stupidly overpowered. If she was a third-generation character, odds are good that the endgame would have nearly zero challenge.
Narm: Some of the enemy attack animations are ridiculous, such as the Giants pointing their fingers, Grinders wiggling their ears, and Clops flexing their pecs while blinking.
Nightmare Fuel: The Lashutemusic is, despite being just 16-bit video game music, absolutely unnerving and terrifying to listen to, and it grows on you as you travel through the dungeon. The fact that, on your second visit, you're greeted with "Death awaits you in Lashute, fool!" turns from Narm to horror when you're listening to this soundtrack. It's a perfect buildup to the game's penultimate boss.
That One Level: Wren's Cave serves as a pretty effective wake-up call for the rest of the game. You only have Rhys and Mieu in the party, money is extremely tight on Aridia, and worst of all, if you came to Aridia without optimizing their equipment, you'll be disgusted to find out that the shops don't sell anything they can equip, so you're going back to Aquatica to grab gear from Rysel. Oh, and did we mention that once you do find Wren, he comes completely bare of equipment save for a measly Escapipe?