A strange little side quest
Here is a rabbit hole for the next loading screen in Multigun Arena 3D: Doom changed game design and distribution in 1993 by separating its engine from content and spreading widely through shareware. The timeline takes another interesting turn: Computer Space reached arcades in 1971 and became one of the earliest commercial electronic arcade games, even though its controls proved demanding for many players. That long chain of experiments is part of why action games still feels fresh when a game finds the right twist.