Back when games were just playable on discs, people were excited that games could hold more content, better graphics, and have better space to put their games since cartridges were too big. All of this became true. But however, the discs had terrible loading time that usually takes from a minute to a hour to actually start the game.
One of the most innovative solutions to this seemingly unavoidable problem was found by Namco way back in 1994 - the company included a copy of Galaxian with Ridge Racer which could be played while the game was initially loading up. It was such a good move that Namco repeated the trick for other PlayStation titles. But however for unknown reasons, they registered a patent to protect the idea. (So technically, no one can have playable mini-games during load times.)
But of course, you might ask: "What about the mini-games during loading times in Splatoon and Star Wars Battlefront?
Well because the patent has finally expired. Now we can see mini-games in tons of games now, including Kingdom Hearts and Smash Bros!
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