Back in 1995, Namco threw in a playable, miniature version of the arcade classic Galaxian to keep players amused during the lengthy loading times for PlayStation launch title Ridge Racer. In the decades since, other developers have largely been prevented from copying the idea of minigames on loading screens. That's because of a broad US patent Namco got for games that prevent "unnecessary wastage of time... by first loading the smaller, auxiliary game program code into the games machine, before the main-game program code is loaded, then loading the main-game program code while the auxiliary game is running."
Some games, like FIFA and Bayonetta, have managed to skirt that patent by including load-screen minigames that are simply smaller versions of the full game rather than "auxiliary" games as mentioned in the patent. Still, for the most part, developers have been forced to use those unskippable load times to display concept art or in-game statistics rather than playable diversions.
The dark era of dull loading screens may finally be coming to an end, though, because the 20-year term on Namco's 1995 patent expired last week. To celebrate, a number of indie developers are getting together for a Loading Screen Game Jam, devoted to "creating interactive loading screens... and defiling the patent that held back game design for so many years!"