Sonic the Hedgehog Pocket Adventure
In August 1999, SNK announced that they were collaborating with Sega to develop a "Sonic the Hedgehog" game for their Neo Geo Pocket Color handheld system. The game was developed by SNK, with supervision from Yuji Naka and Sonic Team at Sega. This marked the first time Sega was directly involved in the development of a "Sonic" game for a non-Sega platform. The team planned for "Sonic Pocket Adventure" to be a return to the classic 2D gameplay style found in the "Sonic" games on the Sega Genesis. In particular, many game design and visual elements are borrowed from "Sonic 2". The game's background music tracks are also 8-bit renditions of music from "Sonic 3". "Sonic Pocket Adventure" was released first in North America on December 4, 1999. SNK released a system bundle with the game included for the holiday season. The game was released in Japan two weeks later, and in Europe in February 2000.
Sonic Mega Collection
"Mega Collection" was developed by Sonic Team, the studio behind most games in the "Sonic" series. According to director Yojiro Ogawa, Sonic Team's goal with the compilation was to introduce children to older games in the series and showcase what made "Sonic" successful. Sonic Team chose to focus on including all the Genesis "Sonic" games. Rather than porting them from the Genesis, they collaborated with VR-1 Japan to develop an emulator to run the games' ROM images. Series co-creator Yuji Naka, who served as producer, said the team intended to include the 1993 Sega CD game "Sonic CD", but storage constraints prevented this. Sonic Team also considered including BlueSky Software's "Vectorman" (1995), and "Sonic R" (1997) and "Sonic Shuffle" (2000) were expected to appear in "Mega Collection" at one point. "CD", "Vectorman", and "R" later appeared in "Sonic Gems Collection" (2005), a successor to "Mega Collection" focusing on rare "Sonic" games. Sonic Team had trouble gathering materials for the compilation because it had been a decade since they made the games and "Sega's not that good about keeping history." For instance, Naka wanted to include the original prototype of the first game but Sonic Team could not find its ROM image.