Masquerading as a movie, Michael Bay's latest sci-fi extravaganza is an almost three-hour-long video game, relentlessly promoting Has-

bro toys and what-turns-out-to-be disgruntled Chinese sponsors.

It begins with alien spaceships attacking dinosaurs. Eons later, an officious blonde scientist is in the Arctic, inspecting the metallic remains of a Dinobot, declaring that it will change our view of the history of the world. Then there's a perfectly coiffed, exquisitely made-up "schoolgirl," clad in short shorts, opening mail on a farm in the Midwest and a government agent declaring that all Transformers must be wiped out. These scenes are disjointed and disconnected, as are most that follow.

Thinking he's buying scrap metal, a Texas inventor, Cade Yeager (Mark Wahlberg), acquires a battered, old truck which turns out to be the badly injured Autobot leader, intrepid Optimus Prime (voiced by Peter Cullen, who has been lending his stentorian tones to the cartoon series since 1984). Widower Yeager is raising a rebellious 17-year-old daughter, Tessa (Nicola Peltz), who, not surprisingly, has a race car-driving boyfriend, Shane (Jack Reynor). Meanwhile, there's this scientist (Stanley Tucci), working for a nasty Black Ops bully (Kelsey Grammer) and a subversive "seed" origin story about Dinobots being created as weapons by ancient Autobots. The newest mechanical villain is Galvetron, created from the remains of Megatron, the evil Decepticon destroyed in 2011's "Dark of the Moon."

Illogically scripted by Ehren Kruger and self-indulgently directed by Bay, this fourth installment in the "Transformers" series is completely incoherent and filled with massive explosions, which demolition experts who work on his movies refer to as "Bayhem."

If you opt for 3-D, you're lavishly showered with splintered metal debris, accompanied by deafening noise.

On the plus side, Industrial Light & Magic's CGI robotic shape-shifting is seamless, and Mark Walhberg is a far more appealing protagonist than Shia LaBeouf, who propelled previous films.

On the Granger Movie Gauge of 1 to 10, "Transformers: Age of Extinction" is an abysmal 2. Unless you're really into techie toys, it's excruciating to watch -- a tortuous endurance test.