Corrected entry: When the kids are dancing near the fire, you can see that their wooden spears are not sharpened on either side. But when they kill Simon they are sharpened somehow.
Corrected entry: When the other boys drop the rock on Piggy if you watch in slow motion you can see that the rock collapses and springs back.
Correction: The rules of the site are clear. If you have to use slow motion to see it, it's not a mistake.
Corrected entry: When Simon is floating in the water after being murdered, you can (barely) see him swim away. Pretty impressive, considering that he is dead!
Correction: He's not swimming, it's the water hitting him and moving his arms.
Corrected entry: Piggy's glasses get broken, and he starts crying about them, but later on he's wearing his glasses again which some how get fixed.
Correction: Yes, he's wearing them but one of the lenses is cracked. The other lens is still intact, so he can at least see correctly out of one eye.
Corrected entry: This is also in the original Golding novel - Piggy is nearsighted, which is corrected with negative (diverging) lenses. A positive (converging) lens is necessary to focus sunlight. However, the boys use his glasses to make fire, but they would not work.
Correction: Of course they would - if held backwards.
Corrected entry: In one scene, when Piggy and Ralph go for a walk, Piggy suggests to build a sundial because there is no watch left after the accident. Later, after Simon's death, you can see Piggy with a watch around his left wrist.
Correction: It could have been damaged or broken, especially when you consider that when this was made/written, watches were not always water-resistant.
Correction: I looked multiple times even in slow motion and you can't tell whether the spears are sharpened or not in that scene. Perhaps him being killed makes you assume so, but he could have died from blunt force and not from the sharp edge.