Eclipsed by the Remix: The Alstroemeria Records remix is orders of magnitudes more popular than the original in-game version. Consequently, most "Bad Apple!!" remixes are based on that remix rather than the original, with the latter seeing relatively little coverage of that sort (such as "Koakuma Ringo" by Yuuhei Satellite).
Gateway Series: Many Touhou fans have stated that the shadow-art music video for "Bad Apple!!" introduced them to Touhou Project and its fandom.
"Bad Apple!!" on everythingExplanationThe shadow art video's distinctive visuals and simplistic color scheme made it a compelling reference for visual benchmarks, resulting in it being recreated in a number of different mediums (such as demoscene demos), similarly to "Doom runs on anything".
The Cirno News NetworkExplanationShortly after fan remakes of the shadow art video took off, CNN produced a report about the phenomenon that quickly garnered infamy among Touhou fans for its large volume of inaccuracies. Consequently, the fandom began joking that the report's poor quality was due to Cirno (The Ditz of the Touhou franchise) running the network that day.
Signature Scene: "Bad Apple!!" has signature shots - specifically, two of them:
Marisa catching the apple and snacking on it as the camera pans to show her flying towards the Scarlet Devil Mansion.
Flandre striking a pose and giving a Slasher Smile, whereupon the video suddenly flips from white-on-black to black-on-white and is then bisected by Youmu.
Signature Song: "Bad Apple!!" is by far the most famous song by Alstroemeria Records, and is arguably the most famous Touhou-related song periodnote its only real competition in this regard being "U.N. Owen was Her?" and "Beloved Tomboyish Girl", which are both from the most-known game in the series, Touhou Koumakyou ~ the Embodiment of Scarlet Devil, and have spawned a few notably famous remixes of their own, but it depends on how you look at it since those few remixes don't necessarily reach the individual popularity of the remix of "Bad Apple!!", official or fan-made.