I'm honestly not sure if I like the nonlinearity part, specially when considering the focus of the contest is speed; it would be way too hard to make a intricate, nonlinear but still very fast-paced level, imo.
Still unsure if it would get many people interested to join the contest.
It's fine to go though, but you could add something else more interesting so that you would get more people to join your contest? Tiny suggestion of course.