Prince of Persia: The Forgotten Sands Walkthrough 01 - The Ramparts

You begin your adventure on the ramparts. There's a battle going on, but you won't fight in it. Instead, you will have to get inside the palace. Go forward and jump over two holes in the passage.
Inside the tower you will meet the first enemies. They're just normal soldiers, so a couple sword slashes is enough to deal with them. There's no way to block in this game, however you can dodge an attack by rolling away. After you're done with the enemies, run up the wall on the right side of the locked door and repeat this once you're on top to get out of the tower and onto the second part of the ramparts.
The prince has wallrunning in his blood, so press and hold down the wallrun button once you're by the edge and don't let it go until you reach the other side. It's very important, as if you let go of the button too early, the Prince will fall down and die. Defeat the enemies (you can try to knock them down the pit) and move on.
Make a wallrun and them run up to grab a fissure in the wall. Pull up, move left pass the curve and lower yourself. Afterwards keep on moving left until the very end. Now use the button combination which makes the Prince run up walls and get to the fissure above.
Move to the left and wallrun to the next fissure. Go pass the curve and lower yourself once.
Once again move to the end and use the wallrun to jump onto the next part of the wall. You will have to fight a big group of enemies here; you can try and knock some of the down with a kick.
After you deal with them, run along the wall and destroy the vases blocking the way with your sword. Note that red orbs will orbs will appear and regenerate the Prince's health. Further in the game you will also come across blue orbs, which regenerate energy. By destroying 100 vases and sarcophagi, you'll receive the [Trophy - Anger Management].
Inside the room, run along up the wall twice, move the analog stick in the direction of the jump (left in this case) and jump - the Prince will grab the fissure on the other side. Pull up, move left and perform another jump.
Wallrun, get to the fissure above and run along the wall left again.
Once you reach the end of the fissure, move the analog stick left and perform a jump. You will once more reach the ramparts. Run above the missing fragment.
Do a wallrun and grab the fissure. Begin moving left and then once again run along the wall to the left - the Prince, once he's by the flag, will automatically take out a knife and ride down the flag, cutting through the material.
Do some more acrobatics and ride down another flag. Once you're below, you will have to perform a new move. Run along the wall for as long as you can and then jump while moving the analog stick in the desired direction. The Prince will jump off the wall and safely land at the balcony fragment.
Jump onto the flag and you will land by a round switch on the ground. Walk onto it and then kill the enemies. After the fight walk onto it again and quickly go through the opened door. You will receive the [Trophy - Memories of Azad].
Do a wallrun and jump left by the end to land in a safe spot. There's a longer sequence ahead of you. Firstly a wallrun, then a jump left and another wallrun to the other side.
Run along the wall which will activate the button found on it and then jump to the right. Quickly run through the closing door. Do a roll if needed.
Run up the wall twice, go left and then up again.

Prince of Persia: The Forgotten Sands Walkthrough 02 - The Fortress

Go across the beam to the other side and jump onto the flag - the Prince will ride it down to the lower level. Defeat the enemies found there.
Begin climbing using the fissures and once you reach the end, run left to the beam.
Go along the beam to the left and run to the upper level. Jump to the next beam and then onto the flag.
Kill all the enemies. You will see some stones sticking out of one of the walls. Use them to climb up.
Once you reach the end, run along the wall. You will activate a switch, which will make two big beams come down and allow you to move on. Quickly do a wallrun while making use of them and then get onto the next beam with another wallrun.
Walk across the beam to a big column and run up to grab a fissure. Move right and climb up sing the stones. Move to the right side this way.
From the beam, jump onto the stones sticking out of the wall. Once below, roll through the hole to the other side.
Defeat every enemy here and afterwards jump onto the wooden construction.
Move up. From the highest level, run along the wall to the right for a bit and jump towards the beam sticking out of the wall. From it, jump onto the jutting out stones.
Move along the stones to the right, towards the exit.
Run along the wall and jump right to reach a beam. Afterwards jump from one onto another.
Jump off the last beam, go through the door. Afterwards jump onto the opposite wall and go down using the stones.
Jump from one beam onto another again and then do a wallrun to reach another one.
Reach the wall. Use the stones and then run up to reach the upper level, there the Prince will be able to greet with his brother at last. You will receive the [Trophy - A Warm Welcome].
For Malik to be able to move on, you first need to activate the mechanism which opens the door. Run up the wall while standing on the beam, which will activate the first switch. Afterwards quickly run to the second one. Once you activate both of them, the bars will open and you will be able to reach the third switch.
You have a time limit for doing it, so quickly jump and run up the wall to activate the switch. After you're done with it, go back a little and jump towards the fissure in the wall. Move right, do a wallrun and jump towards the ledge.
Do a wallrun above the locked gate. From there, run along on the wall again and jump left towards the stones.
You will encounter shielded enemies for the first time. To defeat them, you have to firstly kick and hit once they're exposed. Defeat all the enemies and run up the wall, activating the door opening mechanism. Quickly go through it to the other side.
Kill the rest of the enemies. At the end of the corridor there's a switch which opens the door. Jump onto it and quickly go round the corridor to get through the newly opened door before it closes.
Do a wallrun and continue going left while holding onto the bricks. You will get to the palace. Look at the round columns - jump on to one which's round from the very base, climb it up and jump onto the second one.
From it, onto to yet another. While holding to the last column, climb up to the very top and jump onto the balcony.