By 1928, Disney was one of many animators in the movie business. That year, he was forced to surrender the rights to Oswald Rabbit and tried one last ditch effort to stay in the business by joining his brother Roy in California. On the train from KC to LA, he thought of an idea to put talking cartoons into the new talking movies. He drew Mickey Mouse and the rest is history. Without Disney, the business was still in infancy and the market for animation was still open-ended. Not having the Disney characters does not kill animation as there will be market gaps to fill.
In the meantime, Universal Studios had the rights to Oswald Rabbit. Chief cartoonist Walter Lanz turned out to be far more successful with his own talking creations (Woody Woodpecker) than those taken from Disney.
Disney's most unique contributions were:
* The fantasy character element, talking animals that only barely resembled real animals.
* The full-length animated movie, beginning with Snow White.
* The theme parks based on a cartoon universe (and development of Anaheim and Orlando). The placement of a major league baseball stadium in Anaheim was very much influenced by the presence of Disneyland. Disney World literally allowed Orlando to grow by siphoning tourist business from coastal locations.
Since Disney died in the sixties, I don't see much impact on video gaming. Perhaps animated characters would look more like real people and real animals, but who can say?