it doesnt play the same way exactly, there are minor differences but these differences can also make the game crappy... that difference is aiming and movement... aiming and movement in a 3ps can be quite a chore, you just wont have that solid fast pace feel if you dont explore options of getting the camera perfect... and aiming goes down the drain if youre making an overtheshoulder view and you want youre player to look at an enemy around a left corner...so to correct that, a cover system or camera switching mechanism is needed, both in which have their flaws...

cover system flaws:
-player as less control and the overall experience(to me) is reduced
-i always feel as if i'm doing what the designers WANT me to, ever realize how that piece of cover is just strategically placed infront of the door the enemies will be running from so you can cover an pop em one by one

camera swtiching flaws:
-EXTRA button config needed, sure you can meke it automatic, but your levels would then have to be designed for that so it doesnt DESTROY the players experience, imagine strafing left an right in a corridor and the game automatically switch the cam from your left shoulder to your right because it detects a wall... that could potentially break the game....
-animations have to be design to look good from viewing the character from both left and right shoulder views..

once again, feel free to argue these points ad that is the point of the thread and also feel free to ideas you would like to see in an 3ps...