• In general, positive-feedback loops that increase the difficulty for the player. An example would be shmups where being hit causes not just the loss of a life, but the loss of a level of one’s precious weapon power, or something like that. That means that when one is doing poorly, the difficulty also ramps up. There’s some degree of this in many games insofar as it might be harder to play when one is weaker, but in the shmup case, I really don’t think that it’s necessary — a game would be perfectly playable without that element. I don’t really like situations where it’s just added for the sake of being there.

I hate this mechanic so much. If a player couldn’t win with the powerup, all taking it away does is consign them to a slow death spiral. This made sense when shmups were quarter-munching arcade machines, but this “feature” remained a staple of the genre even after it moved to home consoles.

And for a non-shmup example, Super Star Wars was another major offender. The game was incredibly hard even with a maxed out weapon. Dying reverted you to the basic blaster, cutting your damage output to a fraction of what it was and making it nearly impossible to get past the tougher boss fights if you didn’t win on the first try. It’s often considered one of the hardest games of all time, and I’m willing to bet this mechanic is the main reason why.