What makes the Sun and Moon animatronic work as an FNF opponent is the same thing that makes it unsettling in Security Breach: the two-sided nature of the character creates visual unpredictability. Most FNF opponents have a consistent idle animation you can tune out once you have seen it. The Daycare Attendant does not give you that. The shift between Sun and Moon states keeps your peripheral vision processing something it cannot fully ignore.
FNF Daycare Deathtrap vs FNAF Security Breach uses this intentionally. The stage lighting changes as the character switches between its two modes, which mimics the lights-on lights-off mechanic from the source game. It is a translation of a survival horror gameplay concept into a rhythm game context, and it works better than it has any right to.




