Very good challenging game (walkthrough included)
I have to put it in 2 parts but here's the walkthrough.
Level 6
Kinda hard to explain so i'll draw it.
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Arrows are nails, hope that will do the trick for you.
Level 7
This one confused me for a while.
First click those circles in the middle and move them to a corner, then one by one move them to their right place by looking at those red bars, if they get smaller you're getting closer and once there is no red you're at the spot, click here to put it down.
Once you've done this and they've all turned light blue starts moving those umm things so that all the rings go over their corresponding circles, because of the different distances between them there is only one way to do it.
If you did it right it should form the number 2 and the box will be unlocked, just type 2 there and go on.
Level 8
Once you have turned the boxes the right way so you they connect the first to the one with the arrow you have to cut the logs to fit between the boxes and still be a bit in the dark grey parts, you have the orange thingies to help you with that.
And when you need to put it horizontally move your mouse to the end of the log and some arrows should show up, you can now drag the end to turn the log.
If you know how it works this level is pretty easy just annoying because of all the cutting.
Level 9
First of all there are 2 options and you have to move that big bar to alternate between them.
The point of the puzzle is that everywhere a blank square is overlapped by a colored square you color the blank one to have the same color, just do this every time you see an overlapping while moving the bars with the original menu.
Level 10
First of all move all the cards somewhere to the right.
This is my personal favourite, here you have to reconstruct the music you can hear by clicking the top play button.
To do this listen to the first fragment (you can see the music advance and the first part is the part next to the first color) then find the same fragment below by moving every symbol to the front and clicking on the bottom play button.
When you find the corresponding one find the card with the same symbol and put it to the left, repeat this for the entire song everytime putting the folowing card next to the previous until you have them all.
When you do arrange the symbols below and the colors on the left to be in the same order as the cards.
Beware that the position of the cards is also important that's why i told you to start arranging them from the left.
Well i hope this helps someone, it may not give any satisfaction to solve it this way but i know from experience that you can stop banging your head against the wall because you at aleast understand how it's possible.