>Problems with game design and behavior, beyond difficulty and progression, there's other problems in the overall game design.
Examples of this is not being able to catch Pokemon in the wild areas until you got a badge allowing you to do so, which usually covers your current level. Meaning if you find a level 31 shiny or a level 31 pokemon you really want, you won't be able to catch it until you go and beat the next gym.

What the fuck