Introduce a mechanic (e.g., On/Off switches), repeat it with light variation, then subvert it in a surprising way. Avoid random enemy spam.
Thus, v393216 is a phantom or placeholder—possibly a developer test build leaked via CDN, or a relic of a scrapped “World Maker 2.0” update. Super Mario Maker 2 -01009B90006DC800--v393216-...