Indy is pretty cool, although not stellar. This game has a great sense of speed; it really feels like you are going 200 mph. The licensed Indy track is kind of meh, but the other two tracks are pretty fun. The second track is a blatant rip-off of Laguna Seca with the corkscrew turn, so that is pretty cool.
There are a few secrets, like mirror mode and reverse tracks to keep things fresh. Also, you can enter a code and change your car to the pace car, which adds a little variety. All in all, Indy is a decent game, and it never got ported, so playing it on a dedicated ca is the only way to play it.