Speed is a smaller window, not a new game
When Endless Runner, Snake Rush, or Slash Dash accelerate, the rules stay the same. You still jump, turn, or slash. What changes is how far ahead you must look. Players often respond by tapping faster. The better response is to move attention farther forward and make fewer, earlier decisions.
We speed up instead of adding random cheap hits because the player can rehearse the same pattern. Randomness that cannot be read is not difficulty; it is noise. If a hazard cannot be anticipated with practice, it does not belong in a five-minute arcade game.
Practice the slow version on purpose
Early seconds of a run are a gift. Use them to establish rhythm: jump height, paddle center, slash length. When speed arrives, keep that rhythm and drop optional greed—extra coins, extra fruit, extra edge shots. Survival at high speed is usually a trimmed version of calm play, not a new personality.
If you only ever play until panic, you only practice panic. Take a run where the goal is ten clean actions, then stop even if lives remain. That kind of ending teaches control. The accelerated ending will still be there when you want it.