This string of characters was actually the original title for the arcade game Q*Bert. It was quickly changed when the suits realized that nobody would know how to pronounce this title. A few machines were still shipped with this name adorning the marquee. Those particular machines are even more valuable than normal Q*Bert machines. The "@!#?@!" marquee alone often sells for a hundred dollars or more.
They may have changed the title, but the phrase remained alive, as this is what Q*Bert says whenever any of the bad guys get him.