Whenever I start a video game series I being with the first entry. This way you don't have to deal with taking a step back in game play mechanics. I say this because as I was looking into jumping into the second Phantasy Star Portable I kept running into the advice to just skip the first game which I had really enjoyed.
After finally checking out the second entry in the series I can see why so many people said to just skip to the second entry. This game improves on every aspect of the game significantly. There is built in online Co-op, various multiplayer modes, polished game play and from the looks of it a more well rounded story mode. The only thing I can think of that's not as good as the first is that there's less voice acting. Though that's not much of an issue as I never really played PSP1 with the sound on.
One of the biggest improvements I've noticed right off the bat are the more sophisticated dungeons. In PSP1 the most complex of dungeons have you finding upwards of four keys before being able to advance. Not very engaging. While I've only put a few hours into PSP2 I have noticed the dungeons pulling out a few more tricks. Pressing switches that open a door for a set amount of time sometimes in tandem with teleporters add just a touch more complexity. I hope this trend continues with more involved dungeons as the plot advances.
The enemy selection is also nicer. There are more humanoid enemies for battle which is something I liked seeing. The monster designs are amazing but sometimes there's nothing better than battling an enemy with similar abilities. As things stand I'm really enjoying the game and dying to get into some of the co-op. I've had a hard time finding anyone to play the game with and have harassed all of my PSP owning friends. Expect a more in depth review once I've finished this game.