Airforce Delta, known as Deadly Skies in Europe, is a video game released in 1999 for the Dreamcast. It was both developed and published by Konami. The game is a 3D aerial combat simulation, featuring many jet fighter aircraft. The game is single player only and has been compared to Ace Combat by GameSpy and GameSpot. At the time of the game's release, Airforce Delta was the only combat flight simulation game available for the Dreamcast. A Game Boy Color version of Airforce Delta was also released in 2000. A sequel, called Airforce Delta Storm in North America (Airforce Delta II in Japan and Deadly Skies in Europe), was also released for the Xbox platform in 2001 and for Game Boy Advance in 2002. The Game Boy Advance version, while having the same name as the sequel, has a plot based on the previous game in the series, Airforce Delta. A second sequel, called Airforce Delta Strike in North America (Airforce Delta: Blue Wing Knights in Japan and Deadly Skies III in Europe), was released for the PlayStation 2 in 2004. A third sequel, and a Fourth Game, called Airforce Delta Alternative, was released for Mobile Phones on 2007 Exclusively in Japan only.