I have a simple racing game with 18 different tracks in it…Do you think I should make more?
My initial goal was about 30 tracks…
I think 18 is good. F1 2010 has 19 and it was a recent AAA title…
The reason why I thought making 30 different tracks is because the game is a very simple one,the AI is not so smart,it’s very basic so I thought by making more tracks I would compensate the simplicity of the game.
It’s actually my first game in Unity.
Can you race them in reverse? That’s always a cheap way to double up the number, and most of mine offer a different challenge going the other way round. I think I’m aiming for 16 unique tracks (doubled to 32) and the ability to add more as download/purchase.
Make one track so good that it’s the track everyone wants to play over and over, then the total number won’t matter
Think of Counter Strike and how many maps it comes with, I mean there’s de_dust, de_dust2, cs_office, cs_havana, …?
Less maps of high quality is better than tons of maps no one wants to play
How could you forget de_aztec? 
I would agree on making ones you have as playable as you can, rather than new “filler” content.
Beetle Adventure Racing on the N64 only had 6 courses. I have played that game for hundreds of hours. I used to rent it a lot and play it for full weekends. Last year I purchased a copy of it for my N64 and I still play it. If you make the tracks interesting enough, even 6 can be plenty. Also, the AI in that game wasn’t stellar either. Look up some videos for it if you want to. It’s my number one favorite racing game of all time.