This all stemmed from a while ago, at Schlemmons house, with friends, when my friend Matt said that if you swapped the characters over from the two games, that Assassins Creed was still better. I was unsure as to what he meant. So here i will compare the difference.
Firstly, Prince of Persia is much more level based. You have to finish each level to move onto the next.
Assassins Creed is more a free roam - completing missions can be done at the discretion of the player.
Therefore, first off, taking the characters in mind, the role swap of the two could not be achieved without extreme loss of function. For instance, Prince of Persia runs up the occasional wall, and does the odd acrobatic sequence. Most of Prince of Persia is the logic behind the puzzles, and getting it right, and, of course, the fighting. Ezio, being an assassin does a lot more free-running and [should do] a lot less open fighting.
If you put Ezio into a POP fight, you get nowhere. Sand monsters don't attack like guards do. Ezio's current weapons would all be pointless except the sword. Because there are so many enemies at certain points, using hidden blades, would only kill him.
If you put Prince of Persia into Assassins Creed you'd get clumsy climbing, and appalling assassinations. This would be due to, not only the princes single weapon, the sword, not being stealthy, but because he really isn't made for that purpose. Not to mention his new 'water powers' would be useless in a real fight.
If POP was made to free foam, the game dynamics would change dramatically. The levels would not play the same. It'd be like if you had a massive field for a racing game, and you could go anywhere in it instead of following a track. It has not been built for that.
Ass Creed is, however, occasionally put into a level-progression dynamic. Such as inside 'vaults' and the fact that you can't progress without certain missions. But the levels used, the actual maps, are not 'level following'. They are just places where you can go regardless.
Therefore I think saying that these two games can be compared is quite unimaginable, however, I also think that both of these games can be compared somewhat.
They are both male characters as leads, and have female roles cast as secondary [but non-playable] characters. (AC2, obviously has men too, but here we are being comparative).
Both of them have progression of enemies in difficulty level. The guards on Assassins Creed become tougher and better, Sand demons become harder to kill, with 'bosses' [or titans?].
They are both set as 2 characters that have a problem, and in the most recent games' case, both lose a brother. The Prince loses Malik, to Ratash, the Djinn sand demon thing. Ezio loses Petrucio [to somebody?].
So they both have a space for brothers. Which I think is what they might be, but they are not twins that could be swapped round.