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.
Base Breaker: candii, from the upcoming Append Travel for Jubeat Copious. People either are upset because there is a Vocaloid song, or really don't care.
Ear Worm: This being a franchise with thousands of songs, you're bound to find a few.
Fan Dumb: Unless you have a high tolerance for elitism, you may not wanna hang around IIDX's or DDR's fanbases for too long.
Fan Hater: DDR and PPP get this ("Haha, look at that retard flailing on the machine!"). Especially the latter, and ESPECIALLY if you're male.
Then there's "Juicy", with the artist credited as "kors k Lovers DJ YOSHITAKA". This is without getting into the lyrics, which are sung as a duet between Yoshitaka and kors k.
Nightmare Fuel: Dance ManiaX 2nd Mix's DANGER screen. It's a skeleton on a red background that is reaching its arms out at you. Talk about an incentive to not fail...