Finish the game with all nine life upgrades and obtain the Water Sword

To get this weapon you'll need a sword that can break walls. In the Mechanical Pit (Present), go to the room with the fireplace at the top of the pit, where you once fought a Brute. At the back of the room there's a passageway that bends to the right and dead-ends at a water pit. Drop into the pit and you should see a section of wall with light shining through it. Break this wall to expose a weapon rack. Break the rack and you'll be able to pick up the Teddy Bear, an unbreakable secondary weapon that does minimal damage, but restores some health to you every time you hit an enemy with it.

To get this weapon you'll need a sword that can break walls. In the Mystic Caves, after you get past the first gate that you had to unlock, you'll reach a passage that's divided by a pit with a switch on the floor. Drop into the pit, and at one end you'll see a breakable section of wall. Break this wall to expose a weapon rack. Break the rack and you'll be able to pick up the Glowing Sword, an unbreakable secondary weapon that does a ridiculous amount of damage, but will gradually cause increasing damage to you each time you use it.

First you'll need the Scorpion Sword. When you return to the Central Hall during the Throne and the Mask stage of the game, rotate the lever so that the ground level gap is covered. Then head down the path you took to get the Life Upgrade earlier but this time rather then going in to door turn right and break the part of the wall with sand coming down. The Hockey Stick is in the weapons rack.

In the main tomb in the Catacombs, going through the exit triggers a Dahaka chase. On the 2nd and 3rd chases through this exit, you'll come to a branch in the passageway. If you turn left at the branch, there's a weapon rack hiding immediately to your left. Break the rack and you can pick up the Rayman Glove, an unbreakable secondary weapon that does minimal damage, but knocks all regular enemies to the ground with one hit.

To get this weapon you'll need a sword that can break walls. In the Garden Hall (Present), starting from the middle passageway at the very top of the hall, do a wall run to the rope, then a wall run to the central platform. Turn left and walk directly through the wall of rubble in front of you. You'll turn around and grab the platform you were just standing on. From here, jump across the gap to the next platform. To your left you'll see another platform with a switch. Make your way there, hit the switch, then return to the platform you were just on. There will now be a block you can climb on. From the top of the block, do a vertical wall run + jump to reach the beam above you. Walk along the beam to the right, then jump to the ledge on the far wall. Follow the ledge around to an alcove. Drop into the alcove and break the rear wall on the right-hand side to expose a weapon rack. Break the rack and you'll be able to pick up the Pink Flamingo, an unbreakable secondary weapon that does moderate damage and knocks all regular enemies to the ground with one hit.

Finish both endings of the game (wtih the water sword and without) to unlock all video and illustrations gallery.

To get the library life upgrade whilst in sandwraith mode one must first get to the point where the Dahaka breaks through the wall. You then climb up onto the rafters like would normally and you should see a broken pillar somewhere on the Dahaka's right side (your left). Drop down onto this and you should end up right in front of the Dahaka. As long as you do not touch the Dahaka he will not hurt you. Now, you simply jump right across the gap in the floor and you should cling onto the next ledge which the Dahaka prevented you from. You then continue to proceed upwards and across to the balcony ledges. However, coming back, you need to be careful. It may appear that the Dahaka has disappeared but in reality he is still there so do NOT try to walk in through the hole but go back up onto the rafters and continue on like normal. Deviating from this path and going out the normal library exit may cause game ending glitches.