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.
Surprise Difficulty: Adventure Mode looks like reliable and fun Crash fare, but anyone who has played the last four Crash games will notice how rotten this one can get. Might also count as a Sequel Difficulty Spike in relation to the Crash series as a whole. The cooperative mode, while no pushover, is easier since evens the odds with 2-on-2 games.
The first game was pretty unrelenting as well, but the last three games before Bash (2, 3, and CTR) were generally softer.
That One Boss: Like CTR, the bosses are a LOT tougher in this game. Even Papu Papu puts up a fight, like in CTR.
Papu Papu's probably the most easiest of the bosses. The other bosses, especially the last one are definitely difficult.
While Ballistix as a whole is infuriating, N. Ballism takes the cake. There are two gimmicks: Magnet powerups that repel the ball and N. Gin apearing and firing balls in a counterclockwise direction. Considering how the computer players can easily get the magnets, the level becomes the hardest Ballistix level, even more than the next one.
The crystal challenges for it and the next one (Sky Balls) are very close in difficulty, though. In N. Ballism's crystal challenge, N. Gin will only attack your goal. This is somewhat alleviated by him shooting the balls in the same location every time and having bigger gaps between each shot, but still. Sky Balls could possibly be even worse. There are red balls that randomly show up this time, and they will kill you in one hit. That doesn't mean you wait a few seconds to spawn again; it means you fail on the spot. Of course, the AI can kick these all day without any issue. If they go through your goal, they don't count off; however, what really makes this a pain is that sometimes the regular balls will, completely randomly, turn red when a computer kicks one, and in many cases, you will have no time to react. Have fun!
Let's not forget the Gem AND the Crystal for Pogo Padlock. For the Gem challenge on single player, you have to score 120 points and the CP Us will need 90, whilst in co-op, you need to score 240 and the CP Us require 180. Pogo Padlock's Gem challenge is difficult because stepping on the spots you already made resets them to normal ones and getting hit will replace your colour with the one that hit you. In the Crystal challenge, the only way to get coloured spots is to hit your opponents. Unfortunately, the enemies can still replace it by hitting you or just stepping on them. Fortunately in the Crystal challenge, stepping on your own spots doesn't reset them.