Doom II in 23:03. A wonderful dose of cacodemon nostalgia.
I played so much Doom II as a kid, I remember I had it split over 5 3.5″ floppies and the first computer I played it on churned it out at a painstaking handful of frames per second. The only way I could get it to play at normal speed was to reduce the window to the size of a matchbox. I still completed it though, multiple times. Though the rate it played at I would struggle to complete a pair of levels in 23 minutes.