Ding! Level Up! is an achievement/trophy in Prince of Persia: The Forgotten Sands.
Description[]
"Purchase your first upgrade."
Guide[]
When you return to the castle and are swarmed with undead enemies, you will be introduced to the experience system. Very conveniently, this area has exactly 20 enemies which allows you to gain enough experience for your first experience point. Go into your experience tree, add a point to either health or energy, and then apply changes and exit. The trophy will unlock when you get back into the game world.