Los Angeles, California (CNN) -- What could bring Leonard Nimoy out of his newly minted retirement?
How about a chance to riff on one of the most famous science-fiction movie lines that the "Star Trek" legend didn't originally utter himself.
"I'll be back," deadpanned Nimoy, reworking Arnold Schwarzenegger's "Terminator."
Highly illogical? Well, yeah.
And it was not technically a return to acting for Nimoy who, at 79, announced in April that his role as the shadowy William Bell in "Fringe" was to be his last.
But the actor who played Mr. Spock was employed at the Electronic Entertainment Expo on Wednesday to help promote Yoostar 2, a game that its creators describe as the first "movie karaoke" game.
The game, due out around the holidays, uses green-screen technology and a camera to let players immerse themselves in famous movie scenes. It will be available for the motion-sensing Kinect system on Xbox 360 and for the PlayStation Move system.
"Terminator," "Casablanca," "The Blues Brothers," "The Princess Bride" and "Gone With the Wind" were some of the movie choices available Wednesday. The game is expected to offer 60 scenes out-of-the-box, with another 500 available for download, at a cost of about $1 to $3 each.
The game showcased at E3 was, in the words of creators, a "pre-alpha build" and about 60 percent complete.
The playback didn't line Nimoy's image up perfectly with where a scrubbed Schwarzenegger originally stood in the scene. And the camera had trouble reading his movements because of motion in the background -- which could have had more to do with the rugby scrum of reporters and photographers behind him than with the technology.
For his part, Nimoy was shooting for perfection.
After showing off what it would have sounded like if Spock had been trying to hunt down and kill Sarah Connor, Nimoy studied his score.
The screen said "good start."
"Where was the timing off?" he asked. "Can you tell me?"
Then, he jokingly lashed out when told that reporters were interfering with his signal.
"Don't screw up my game," he threatened.
The new "Terminator" was clearly getting into character.