Zak McKracken and the Alien Rockstars
Game dev Torsten "Starkiller76" Schöps:
"As far as I remember we planned the amulet plays a central role, because it was for activating a Scholarian backup defense shield, it could be used as a power source and tofgether with the right gems, it also was a beaming device, beaming the holder of the amulet to certian predefined locations. So you could see it a little bit like Sophia's amulet in Indy 4, which also was used to solve many different riddles or was helping in driving the story forward.
The Rockstar ... that was the surprise ... is a big Deathstar-like-Spaceship, which had the power to send and signal strengthen "emotional brainwaves" derived from music records to a certain area, preferable a planet.
So if you would play a gothic song, people of the focused area would submit suicide, and with punk music anarchy would break out ... and so on. The caponians want to use the Rockstar to conquere the universe, starting at the earth as their first "testing ground". Their target is to conquer the earth without any form of resistance after playing some weird "music cocktail" and on top of that getting the old scholarian defense technics in their hands.
Zak (and Amy) on the other side are trying to prevent that, finding out about the amulet already on the Mars (where Zak is hunting for a "amulet story") and accidently activating parts of the backup system. At the very end of their explorations about the purpose of the system they got kidnapped by the Caponians. But finally made to free themself and activate the system, that then destroys the alien rockstar"