Click on the play button and, on the next screen, pick the door marked "1" to begin the first level.
On Mobile: Choose to have the sound on or off, then proceed with clicking on the play button.
Your objective is to find the blue diamond or diamonds hidden in each level. There are items hidden underneath the carpets that will help you unlock the lock in the screen and get that diamond. However, sometimes there will be obstacles to unrolling the carpets, such as boxes or other objects. You'll have to figure out how to remove them in order to unroll the carpets, find the key and open the lock.
Use your mouse or finger to drag the carpets (from the side that doesn't have holes) and unroll them. If you find a key, it will go in your inventory (the 4 boxes at the bottom of the screen).
Tip: To remove crates from your way, you must collect a magic wand, click on it in the inventory and then click on the box. It will go to your inventory and you can use it on buttons if you want to activate them.