LogFAQs > #971378318

Yeah, Blue was the original "3rd version" from Japan's Red and Green versions. All it really did was improve the pokemon and overworld sprites, fixed a bunch of glitches, and changed up the encounters. It had a bunch of minor things too like wild encounters for Jynx and Lickitung (which wasn't possible in Red and Green), different prizes at Celadon (the same as in American Blue), and HP Up being available in Celadon Store. But otherwise barely anything changed gameplay-wise >_> I don't see it being worth it if you already had Red and Green back in the day.