I came so close, but I couldn't find the second key. A little too frustrating for me - I got half the pieces and parts by randomly clicking, because I couldn't see anything left. Have to give this one 2/5 - almost made it to 3 if it had been just a little more forgiving.
The sequence of levels was changed. So 5-th lvl in the game and 23 in walkthrough video are the same.