And it seems like that I have accomplished the game with 42/40 coins and 0 achievement, that's weird.

I think there is a bug in room 12 the Machine Room with the puzzle where you have to shift the blocks in order to make a mold. Screenshot The blocks were very unresponsive to move around, sometimes I had to try it 20 times before one block finally moved. Sometimes they moved right away. So it took me about 20 minutes before I finished that puzzle (phew). I use windows 10 btw. This is the only issue I found while playing. However something else: making screenshot...

Had fun 'til now. I've read other discussions about this problem. No matter where I click I can't advance from level 14 to play level 15. It's locked up tight.

That would be for me a reason to buy this one

I have found none on the beach and just 2 at Laboratory. Am I missing something?