I've been meaning to write this review for awhile now so here it goes
gameplay
The gameplay is pretty good. Takes some getting used to at first but once you get the hang of it things aren't too bad. Once in awhile you might encounter a slight camera issue. Another cool feature I like is capturing enemy soldiers and then having them join your team. You do have to get used to the new radar system based on sound. The closer you get to enemies or your goal the louder the sound gets and sounds vary between soldiers and the goal so you must learn to tell the difference.
The other thing to get used to is making different teams. There is the spy team that explores the area before the mission and gives you information the better your spy team the more detailed your map is supposed to be. There are the technical and medical teams that make items for you the better the team the better the items are. Of course there is the sneaking team in which the player controls to do the mission. Each character has unique stats and careers that will help you decide what team to put them in.
The game also has some cool online modes to play like online trade. If you don't want a team member you send them out to a server to be traded and Cyber survival which sends your sneaking team to a server to fight and get experience. If your team loses they won't come back and you'll lose all the characters on that team. It happened to me. I lost my best team on Cyber Survival once, which included Solid Snake. There is also the AP scout mode that lets you scan LAN to add new soldiers to your team but some other conditions may apply before you can add a soldier like you have to have another certain soldier on your team. Of course the game also has online infrastructure play.
graphics
I am very impressed by the graphics. The detail in each level is great. You can see so much detail on buildings and even enemy soldiers.
soundtrack
The game has a good soundtrack. I like how the music changes as the conditions change like in all the Metal Gear Solid games. If you go into alert phase the music speeds up and gets loud but when you are stealthy and the enemy is not aware of your presence the music is calm which gives it a good affect.
controls
Like said before the controls get some getting used to since there is only one analog stick and two shoulder buttons. The things I had to get used to is having to hit the circle button to get the weapons menu up and to sneak you have to hold the triangle button while moving. Again like I said earlier once you get used to the controls they are very easy to use.
storyline
There actually is no real story when you are playing the missions. It’s pretty much avoiding the enemies to reach the advance point and repeat. They will throw in special missions where you have to kill all enemies or make it to the advance point under a certain time, etc. The game does give you a variety of levels which kind of steers you away from lack of a story.
Overall
This is a pretty good game for the PSP especially if you are a MGS fan even though it lacks story. I cannot compare it to the other game however because I never played the original Portable Ops. I give Metal Gear Solid Portable Ops Plus a 9/10