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
"Sonic Mega Collection" features twelve to fourteen complete games in one retail unit. All games are ports of their original versions on the Sega Genesis. High-resolution instruction manual scans are included for each game. Also included is an "Extras" section featuring over 100 scans of "Sonic the Hedgehog" comic covers, illustrations of "Sonic" characters throughout the franchise's history, and a handful of videos promoting other "Sonic" games, including the beginning and end sequences to "Sonic CD". In addition to the seven default games, three unlockable games are included that recreated the "Sonic & Knuckles" "lock-on technology" by allowing players access to new gameplay features and special stages by opening the hatch of the "Sonic & Knuckles" Sega Genesis cartridge and inserting another compatible cartridge, in this case each of the first three games in the "Sonic the Hedgehog" series. Also, four games published by Sega but not in the "Sonic" series could also be unlocked (two in the North American version).