After defeating the final boss, Modern Tails & Classic Tails are briefly seen discussing something at Sonic's birthday party during the game's last cutscene. What they are talking about differs between the English and Japanese localizations of the original game.

In the English version, they said:
Classic Tails: He collects how many? Wow, where does somebody put all those gold rings?
Modern Tails: You know what? I don't know. I keep forgetting to ask.

In the Japanese version, they said:
Classic Tails: You added legs to the plane? What have you done to Sonic's Tornado?
Modern Tails: Yeah... I guess really did go overboard with the legs...

In Sonic X Shadow Generations, the English version of this cutscene was completely re-recorded by the original voice cast, where they now say:
Classic Tails: So I have a question for you. Once we're home, you think the timeline will be restored?
Modern Tails: Yep! Just... don't think about it too hard.