RollerCoaster Tycoon®: Deluxe

RollerCoaster Tycoon Deluxe is the GOG bundle of the original 1999 RollerCoaster Tycoon — Chris Sawyer's masterpiece written almost entirely in hand-tuned x86 assembly — plus the Corkscrew Follies and Loopy Landscapes expansions. The Deluxe edition is the canonical "old RCT" most people remember, before the 2002/2004 sequels and well before the modern Planet Coaster era.

This is the version where every guest is a named individual, where coaster excitement/intensity/nausea ratings are calculated per-segment, where the music tracks loop in your head for years afterward. The expansions add coaster types (suspended monorails, plume rides), new themes (Ice World, Medieval, Martian), and three dozen extra scenarios on top of the base park collection. The custom-coaster builder remains some of the most satisfying construction toolkit in any sim, full stop.

Packaged from the GOG release — meaning DRM-free, no installer dance, just unzip and run. 386 MB installed. Single-player only — there's no multiplayer mode in any version of the original RCT.