PC Sonic Riders/Xbox Sonic Riders?

Alright, I bought Sonic Riders (Xbox) when i was a kid and I remember a long campaign and never beating the game. It seemed very long. But I bought Sonic Riders (PC) and beat it. it was like 3 hours of campaign. Plus some tracks I remember were never brought up. so wtf? Are they different? Because I never owned the Zero Gravity so I know im not referring to that....I don't get it.......If the two are different I am going to be pretty mad..