The aim of the game is much like real Roulette. Instead of a ball, however, it is substituted by your car, and you must land on the colour/number of your previous desire. First you must bet a wager, at least 10 <currency here> and then you choose from a colour/number-range or specific number of your choice. Then you must drive into that number. If you win you earn double your wager, losing equals losing your betted wager. Even if this can earn a lot of money, it isn't very popular, like real gambling it is a risk of losing money, since the chances are extremely low of getting a specific number. Although, there are strageties into playing this. Such as, when you see the number 0 accelarate with a specific engine/parts and you will reach a fixed number. However, this is risky too, therefore many people bet low with strageties/luck alike.
Stamp 29 is unlocked when completing Roulette, but only if you win on your first attempt during your visit. If you lose on your first attempt, you will not earn Stamp 29, regardless if you win on subsequent attempts during that visit. If you lose on the first attempt during your visit, exit the building and then re-enter the building. Then try again until you win on the first attempt.