Corrected entry: In order to return to Eternia, Guildor must build a new Key using Kevin's keyboard to make the correct tones. How Keven got his hands on the keyboard in the first place is somewhat suspect, as he claims it was 'at the music shop', however we know for a fact that the shop - along with everything in it - was shot to pieces by Skeletor's henchmen only a little while ago. His must have been the indestructible one mentioned in the other mistake.
Corrected entry: When Evil-Lyn and a robot trooper scan for the key in the warehouse backyard, note in the side views that while the trooper is speaking, his larynx is moving. Robots do not require a moving larynx for voice.
Correction: They are not robots, but regular soldiers. There is nothing in the entire movie to indicate that the soldiers are robotic.
Correction: Yes, most of the shop was destroyed, but it is not thereby said that it would be impossible to salvage something from the wreckage. You can still see undamaged guitars hanging on the wall, and unbroken drums lying on the floor. Besides this, the back room was spared from destruction, as the only fighting going on here was wrestling between Kevin and Lubic. It is possible some keyboards were stocked in the back.
Twotall