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In the game's manual, a promotional campaign was advertised where players could win a "Cool Prize" if they beat the game under certain circumstances. If you beat the game on any difficulty under Hard, use any of the six "UNCOLA" letters as a free continue, or fail to collect any of the letters at all, you will be greeted with a screen featuring a pair of Spots crying because you did not meet the requirements to win the contest. However, if you beat the game on Hard and have all six "UNCOLA" letters, then you will instead be greeted with a screen of a Spot holding a camera instructing the player to take a picture of the screen and mail it to the address in the game's manual, the headquarters of Virgin Games. This contest ended on December 31, 1993, roughly 8 months after the original Genesis version was released, and not even 4 months after the SNES version was released. According to a TV Tropes entry, the prize was allegedly a cheap plastic Spot toy, although there has been no official confirmation on what prizes were awarded to winners, if any.

One known "winner" of the contest years after the fact was YouTuber Jirard Khalil "The Completionist", who reviewed the game and instead of sending his screen to the now-defunct Virgin Games, he decided to tweet it out to 7 Up's official Twitter account in 2014. This caught their attention for being "crazy, old school and incredible", resulting in them direct-messaging him and asking for his address to send him a prize. The following week, a bizarre PR stunt took place where two "7 Up Women" arrived at The Completionist's offices, bringing with them a pallet of assorted 7 Up, Diet 7 Up, Cherry 7 Up, Sunkist and Snapple drinks, as well as free sunglasses and loudspeakers. Khalil described the event: "They had no idea why they were there, I didn't know why they were there, it was an overall weird experience to say the least."
Contributed by MehDeletingLater
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In the European release of Cool Spot, the 7up bottle seen in the introduction was changed to be opaque and contain an S.O.S. note. Presumably this was done to make the plastic bottle appear as a glass bottle, and remove all references to 7up, who at the time, in Europe, already had another mascot known as Fido Dido.
Contributed by Dazz
There's a hidden credit line in the SNES game's ROM which reads:
(C) 1992 Basement Boys Software

Basement Boys Software were a group famous for making hacking tools on the Commodore 64 in the late 80s, who had some members go on to Chip Level Designs, a company that used to provide sound programming for a number of SNES titles. The same credit appears in Bubsy.
Contributed by Dazz