Persian Nights: Sands of Wonders

You can easily get this achievement in the beginning of the game, in the Antechamber. After you speak to Darius, the first hidden object scene in the game will become accessible just behind him.

You will need to find 13 drops of water to complete this hidden object scene, and there are some that are very close together in this puzzle. Simply click any 3 quickly, within 3 seconds, and the achievement will unlock.

Here, I've circled 3 that are very close to one another as they can be clicked very fast and within 3 seconds. Just be careful to make sure that your cursor is centered over each so that it selects it on the first try. Achievement unlocked! :)