Now, it has followed that up by beating expectations at the North American box office in its first weekend on release.
The film made $30.2m (£24.9m) over the weekend, well above predictions of between $17m-$20m (£14m-£16.5m).
"Word-of-mouth is through the roof," said Jim Orr from its studio Universal.
That put M3GAN second in the US and Canada box office chart behind Avatar: The Way of Water, which took another $45m (£37m) as it became the seventh highest-grossing movie in history.
M3GAN is short for Model 3 Generative Android, and the robot is instructed to befriend and protect an eight-year-old girl whose parents have been killed in a car crash.
M3GAN's initial innocent nature soon takes a more menacing turn when it begins to take its duties to protect young Cady very seriously indeed.
When the trailer came out in October, viewers immediately picked up on one scene - when a blank-faced M3GAN does a childlike but chilling dance before pursuing another victim.
That was swiftly turned into a meme with alternative soundtracks from Taylor Swift, Beyonce and Megan Thee Stallion - who gave her namesake her seal of approval - while users also recreated it themselves.