Every level and boss in this game feels fun and fair. The items and secrets are the best in the series so far, and holy shit did the final boss put a damper on everything that was previously established. This boss was genuinely impossible for me to beat until I used a save state halfway through the fight to reset and have a good run. This is probably the single worst final boss in a video game that I have played so far, and by far the worst Wiley in the series up to this point.