I don't really like grid, because it's very hard to see how the track goes and where you mustn't drive. I also think that you could have made more from Rotasnakes, now it's just a plain tri-oval with some banking.
Next, I can't seem to get comfortable with chess, although I found it very strange that I was faster than the Mini AI driving a Mini then if I took the formula.
And I like Hatpin a lot.
Speaking about the illusions and scenery, Grid is surely the best. I didn't really consider the effect at chess to be great, for me it just looked like red squares with lines around them, although I think I know what you intended to do there. Rotasnakes
nice texture, but not really confusing me, sorry, and I also think that the persons at top-right look strange. And Hatpin? quite nice, also not really confusing, but if I see that right, how did you make the different red colours? Is it because of the hmap or is it only because of the illusion? Or am I too tired now?