Start the game with choosing the difficulty. Look around and plan your moves before you make the first step. Collect all white dots and reach the white door as fast as you can.
How efficient you could become? Play this game and test yourself. Here you will play against time and the quantity of white dots. Do everything quick and collect all white dots as fast as you can. When you are done, enter the white door at the end of the level and proceed to another one. Unlock other difficulties, when you'll have enough resources.