hi Pierre,
there's a small bug in the Lake level, where you get the magnifying glass without actually picking it up, if you use any object on the sun rays.
i've tried with all 4 default objects, the 1st spring, the 2nd spring, the 2 springs together, the twigs and the stick from the tree and it happens for all of them.
this is with the Steam version.
love the game btw, hope to see Goblins 7 soon!