Billy Hatcher and the Giant Egg (GC, 2003) was an exclusive Gamecube title released by Sonic Team and Sega.
Once the single player campaign is cleared, players gain access to the Gamecube-to-GBA linking connectivity in which 4 single-player games can be downloaded individually to the GBA: ChuChu Rocket Challenge, Puyo Pop’s Endless Mode, Nights into Dreams (an exclusive demake of the Saturn original), and the easy and hard modes Billy Hatcher’s Hyper Shoot, an exclusive game made just for this Gamecube release.
The GBA downloadable version of Nights into Dreams is also available in the Gamecube’s release of Phantasy Star Online I & II.