Simple mechanics which they are easy to understand and easy to jump into the game. I had the interpretation that the ball that I needed to use would be something I had to manage because I would need to a specific but instead I can use whichever so there is no reason to not always use the big one. You can potentially fix this by either have them be on cool down, spawning at random, or having some sort of indication on the red box to tell you which color of the energy ball it would accept.