In the late 90s and early 2000s it wasn't uncommon for video games to try to compete with the Mario Kart series. I don't know if that was the reason for Batman: Gotham City Racer, but it seems likely. I guess Ubisoft should of mention that the game isn't really a racing game.
Yeah it's not a "go-kart" racing game featuring Batman and friends, or even a realistic racing game with the Batmobile. Instead it's a misson-based game where you can control Batman, Nightwing, or Batgirl and confront the vehicles of famous Batman villains in combat.
The game also had a few other modes, and a multiplayer option. It also featured clips from the animated show.
Despite not being terribly old, Gotham City Racer has been long forgotten by both Batman fans and the video game world. The few that did play it left rather unimpressed reactions. It seems somewhere in Gotham City, Batman took the wrong turn.