Still, I’ll take an ambitious mess over a boring retread, and even at its messiest, “M3GAN 2.0” is lively and fun, full of the same snarky humor and gleeful nastiness as the original.

Any technology we don’t fully comprehend we turn into horror, a truism that reaches back to Mary Shelley’s “Frankenstein” (medical science) and ahead to “The Ring” (VCRs). Of late, the bogeymen have ...