"Transformers Prime Terrorcon Defense," "Transformers Autobot Stronghold," and "Transformers Armada" are some free-to-play online games incorporating characters from the movie "Transformers 4." In "Terrorcon Defense," players control Bumblebee and Optimus Prime in a battle against the Decepticons.
"Autobot Stronghold" is a tactical game in which players protect Autobot HQ from a Decepticon assault. In "Transformers Armada" players defend an energon mine from invading Decepticon units.
Some other Transformers games include "Transformers Quest," "Transformers Bumblebee Blast," and the fighting game "Transformers Showdown."
While there are no online games based directly on the fourth Transformers movie, "Age of Extinction," the above games incorporate characters and concepts found in that film. There is an official "Age of Extinction" game available for download from the Apple and Google Play stores, which can be played on smart phone or tablet devices.