Easy, Regular and Evil! obsolete each other. They do have slight differences, such as increased objects and AI difficulty as you go to a higher difficulty but the differences are so small I chose not to separate them.

So, if you manage to beat someone's time with a harder difficulty, the bragging rights are yours ;)

P.S. Choosing Evil! is actually a good benchmark to see if you're doing good or bad, as you need to perform almost perfectly to win.

Right, so apparently a higher difficulty means higher top speed. Just wanted to throw this in here, as thebpg13 noticed. However difficulties still obsolete each other, probably Evil! won't be that much faster, especially as you have more obstacles to slow you down. The game isn't actively run either