Oh boy, going for the good future has me hating the time travel gimmick, the real enemies in this game are future posts, a more intimidating foe than Unleashed's wasps, carnival night barrel and those exploding star things from metropolis zone.
You want a past post but keep running across future ones, if you make the grave error of stumbling into a future post you're likely to get sent into an automatic tube or spring sequence forcing you kicking and screaming into the future, i'd sooner have Sonic die than go into the future!
I was doing so much better with the special stages until I discovered that water shaves 10 seconds off your time limit, somehow this knowledge has made me worse at them.