Darren Criss stood up, fast asleep, his head heavy. When he awoke, he reverse body rolled, slowly turned his head from side to side, then brushed his teeth, mechanically moving his toothbrush — left, right, left — like a cartoon character.

But this was no cartoon come to life (that would be “Boop!,” playing a block away). This was a scene from the Broadway musical “Maybe Happy Ending” in which Criss and Helen J Shen play Oliver and Claire, android attendant robots called Helperbots.

Playing a character onstage comes with its own process of world building. But playing a nonhuman character requires a different — or additional — calculation. Where is a robot’s center of gravity?

As Claire, a Helperbot 5 with a defective battery (and heavy dose of sarcasm), Shen moves as a human would. As Oliver, a Helperbot 3, an earlier model, Criss moves stiffly, his reflexes stilted. He’s all elbows and knees and sharp lines. Her limbs move in bell curves. The challenge of playing an aging robot has been a field day for Criss, an opportunity to draw upon his formal training in physical theater.

“In many ways I joke that Oliver is my excuse to overact for two hours,” Criss said, adding, “the joke being how beep boop bop are we going here without it feeling too, frankly, ridiculous.”