If it’s worth doing once, it’s worth doing three times. 

  • If you give the player a weapon that’s useful in a certain situation, make sure you can design at least 3 different ways for it to be used.
  • If you make an enemy, show the enemy to the player at least three different ways.
  • If you have a puzzle in a level, give the player at least 3 puzzles to solve in that level.

One important word in those examples is “different.” You don’t want to ask the player the same question 3 times — you want to put a spin on it. Show it once, then introduce two wrinkles.

Don’t let it overstay its welcome.