Maybe it's the second level. It requires using key 1 to examine the four statues. I checked them in the correct order, but nothing happened. I've looked at the walkthrough, yet nothing works no matter what I try.
Viewing post in Latex Island - Public Demo comments
Strange. Admittedly, the puzzle does have a sort of visual issue–the pictures that I’m using are facing one way with their bodies and looking another way with their heads. I suggest using the sprites as a better hint.
Don’t forget that you need to activate the four pedestals, too. Some people have forgotten the E key (legitimately).
If you just want a solution, the one provided in the Solutions section of the walkthrough will work, unless something’s gone wrong with your particular version.