Airport CEO was initially released in 2017 with Alpha 20.7 as an early-access title, and was released to 1.0 on March 4th, 2021. Upon release the game has multiple management systems such as a research progression system, multiple floor construction and large aircraft handling.The following is a summary of some of the early access updates:Alpha 24 (12/19/17)- Enabled Airline Modding- Steam Cloud Support- Modifications to the Airline contract system, simplifying the experienceAlpha 25 (3/14/18)- Primarily focused on improving performance- New path-finding system for guests- Adjusted the default world sizeAlpha 26 (3/28/18)- Continued performance improvements- New Subway entrance for guests- Added the ability to unlock new areas to build onAlpha 27 ("The New UI Update", 6/26/18)- Overhauled the existing UI- Replaced the core flight scheduler- Reworked existing notification system- Added Steam Workshop supportAlpha 29 (1/28/19)- Major performance update, focused on going through much of the old code to increase performanceAlpha 30 ("The Soundtrack Update", 3/26/19)- Developed alongside Alpha 29- Contains an hour of original music composed by Daniel Rosenqvist and Anton Dromberg- New interactive tutorials- Plenty of additional bug fixes and performance improvementsAlpha 31 ("The Multi-Floor Update", 7/2/19)- Added the ability to build both above ground and below ground- Added aircraft cabin cleaning service- New language localization system
