Belgium were also under the Six Flags brands during development and were also included. Many popular rides in Six Flags amusement parks can be used in other scenarios, but are locked from editing. The game also contains a variety of new themes and music for attractions. Guests' AI was improved from the original game, allowing for the creation of more complex paved areas. All of the scenarios in RollerCoaster Tycoon 2 are available at first launch (which contrasts RollerCoaster Tycoons unlocking system), and they are divided into five folder tabs: Beginner, Challenging, Expert, Real, and Other parks. The 'Real' tab contains the Six Flags parks preconstructed, while the 'Other' tab contains their empty versions. When creating a scenario, the player can save to any of the tabs. As with the previous game, players could upload their saved track designs onto the now-defunct 'Ride Exchange.' Track designs from both games can later be imported into RollerCoaster Tycoon 3, where they are no longer locked to the isometric views. Development RollerCoaster Tycoon 2 was developed by Chris Sawyer, who designed and programmed the game entirely by himself in assembly language. Some parts of the game were based on efforts to develop a new version of Transport Tycoon, which Sawyer had been working on as early as 1996. The game was published by Infogrames and released on October 15, 2002. Release Expansion packs Much like with the first game, two expansion packs were released for Roller Coaster Tycoon 2, which included new rides, facilities, and scenarios. Each pack was based around themes and didn't have any involvement from the series' creator Chris Sawyer. Instead, both expansions were developed by Frontier Developments, who developed the Xbox port of the original game, and would go on to develop the entirety of RollerCoaster Tycoon 3 and its spiritual successor, Planet Coaster. The first pack, Wacky Worlds, was released in May 2003. This expansion focused on parks based in different countries around the world, including cultural heritage. The second pack, Time Twister, was released in November 2003. This expansion focused on parks based around different time periods. Re-releases and compilations In November 2003, to go alongside the release of Time Twister, Atari released RollerCoaster Tycoon 2: Combo Park Pack, which was a boxed compilation of the base game and Wacky Worlds on separate discs. In Europe, this was known as RollerCoaster Tycoon 2: Gold Edition. In October