You are Percy protecting Frank as Frank frees Thantoes in Son of Neptune. Click the thermometer to change the temperature of the water. (Percy can do that, I bet.) Press space to use water powers. If you are at 70 F you will throw a ball of water. 50 F summons a fist of water. 30 F summons a glacier wall. 110 will summon a mist that protects Frank. 90 F will shoot a warm stream of water and knock down the icicle into ghosts. If you are touching the puddle, you will gain strength. If you press space while touching the puddle, you will summon a hurricane around yourself, like in the book. 'S' to use your sword. arrows to move. Good Luck!
As I said in the instructions, this is Son of Neptune, when Percy is protecting Frank while Frank frees Thantoes.