66 - not that hard, you just have to line them up from 1-8 in pair of two, because they are linked together, on the bottom line.
67 - on the wall it says <-67-> and on the floor 6=5. The arrow means the number before 67, which is 66, and the number after which is 68. So the numbers are 66-67-68, but because of 6=5, the code is 55 57 58
68 - don't remember winch order I did it in, you just have to try. Or wait 15min
69 - on the wall it says 1,2,3,...,16. And on the floor with the flashlight, there's a grid of 4x4, which contains all the numbers from 1-16. You have to write them down or remember them. Turn of the flashlight and click on the tiles where the numbers are; start with 1 (1st tile on the first row), then 2 (2nd tile on the bottom/fourth row) and so on. here's the numbers:
1-14-16-4
11-7-6-9
8-12-10-5
13-2-3-15
70 - here you have to move the stars around so none of the lines crops each other
When I complete level 20 the game is skipping back to level 13. When I try again it skips to level 8 and so on. Help please? Has this happened to anyone else?