Completist is an achievement/trophy in Prince of Persia: The Forgotten Sands.
Description
"Purchase every item in the upgrade menu."
Guide
When you finish the game, you will not have all upgrades. To finish with the upgrades it is as easy as playing the challenge room over and over until you gain enough experience. Refer to "Prince of Tides" for tips on the challenge room. Once you do this enough times to unlock your final upgrade, the trophy will unlock.