Sega continued to release 2D "Sonic" games. In 1999, it collaborated with SNK to produce "Sonic the Hedgehog Pocket Adventure", an adaptation of "Sonic 2" for the Neo Geo Pocket Color. Some SNK staff formed Dimps the following year, and developed original 2D "Sonic" games—"Sonic Advance" (2001), "Sonic Advance 2" (2002), and "Sonic Advance 3" (2004)—for Nintendo's Game Boy Advance (GBA). "Sonic Advance" was the first original "Sonic" game released for a Nintendo console after Sega and Nintendo's fierce rivalry in the 1990s. It was outsourced to Dimps because Sonic Team was understaffed with employees familiar with the GBA. Dimps also developed "Sonic Rush" (2005) for the Nintendo DS, which uses a 2.5D perspective. Dimps's projects received generally favorable reviews. To introduce older games to new fans, Sonic Team developed two compilations, "Sonic Mega Collection" (2002) and "Sonic Gems Collection" (2005). Further spin-offs included the party game "Sonic Shuffle" (2000), the pinball game "Sonic Pinball Party" (2003), and the fighting game "Sonic Battle" (2003).