* BizarroEpisode: The series. Being Christmas-themed games with the recurring cast not acting like their usual selves is one thing, but the humor gets increasingly surreal to the point that [[LampshadeHanging Proto Man has had enough of it]] by the third installment.
* TearJerker: The post-credits personal message at the end of the third game is a heartfelt account of the issues the [[CreatorBreakdown creator had to deal with,]] including nearly committing suicide. He also thanks certain people directly for helping [[SugarWiki/HeartwarmingMoments save his life]].
* ThatOneBoss: General consensus is that Future from the original game/remake, is by far the hardest boss to defeat Buster only.
** In the original Flash game, the first fight against [[spoiler:Dr. Light]] is a puzzle boss, and without using the correct solution, was declared somewhere between impossible and incredibly frustrating. Ironically, using his correct weakness, he falls in 3 hits. [[CreatorBacklash Even ACE has shown resentment for this fight]].