These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anticlimax Boss: possibly as the result of a bug, Devan Shell has the potential to become this in JJ2 when playing with Spaz or Lori. If you deveat Devan in his first form (turtle, holding a gun) by only using Spaz's or Lori's karate kick, you can defeat his second form (the dragon) with a single shot)
Game Breaker - Sort of in the second game. Spaz's double jump not only gives him a leg up on maneuverability when compared to Jazz, but the combination of running full speed and a well timed double jump can reach most spots in the game, including places you should need a teleporter to get to.
Spaz in general is a Game Breaker. The combination of his super speed, double jump, and sidekick makes going through most levels a piece of cake. When playing online you'll be hard-pressed to find ANY experienced player who isn't playing Spaz.