The Player's Dials

A stuck player needs something to turn. The HUD has offered three dials since it went in: SOLVE, the ◀ ▶ level arrows, and SLOWER / FASTER for the time between rocks. The last one is easy to build wrong.

A dial scales the base, never its own output

The notches are multiples of each level's own interval: 0.75, 1, 1.5, 2 and 3, starting on 1. Press SLOWER three times and you reach 3, the last notch; a fourth press does nothing. A dial must multiply the level's base value, never its own last result, or repeated changes compound. Step through five levels after those three presses and the interval stays three notches slow, never slower:

First Bend, Over the Wall, S-Bend, Asteroid Belt    2.2 s × 3 = 6.6 s
Traffic                                              2.0 s × 3 = 6.0 s, its own interval
The Needle                                           1.9 s × 3 = 5.7 s