The Decepticons have launched a massive attack against the Autobots. In the attack's aftermath, the Autobot base lays in ruins and Optimus Prime is critically injured. Alpha Trion intervenes, mends Optimus's wounds and grants him new flight capabilities. His strength and resolve renewed, Optimus faces off against the Decepticons to defeat them and push them back.
Flying, driving and running over the brushlands, Optimus fights against several Vehicons drones before he encounters Dreadwing. The two duke it out in the skies before Dreadwing is defeated and flies off. After facing off against more Vehicons, Optimus duels Knock Out, who lays down mines in the surrounding area in his bid to destroy Optimus. He too is defeated, and runs off, swearing revenge.
As Optimus delves deeper out into the desert, he faces off against Breakdown (after dealing with more Vehicons beforehand, of course). Breakdown is enraged that Optimus has hurt Knock Out, and attempts to take down the Autobot himself. Breakdown is defeated in turn, and Optimus continues on his journey.
Many destroyed Vehicons later, Optimus encounters Airachnid, and the two of them do battle in the skies. With her defeat, Optimus leaves the desert, and enters a more lush jungle area. Here, after defeating yet more Vehicons, Optimus encounters Shockwave. Though Shockwave puts up a fight with his powerful tank form, he too is driven back by Optimus. Starscream and the Vehicons before him do not fare better. After defeating the Decepticon jet, Optimus moves on to a snowy area.
After peppering the glacial terrain with the remains of many Vehicons, Optimus defeats Soundwave in aerial combat, despite the Decepticon spy having Laserbeak aid him in the combat. Optimus's final challenge yet still ahead; Megatron.
The Decepticon leader takes on Optimus after wearing him down some more with Vehicon cannon-fodder. Unlike his minions, he alternates between fighting Optimus on the ground and in the air. He is also aided by some of his troops returning to the battlefield, with Shockwave, Airachnig and Breakdown all making repeat appearances. Megatron also has the same forcefields the Optimus uses at his disposal. Nonetheless, Megatron is eventually felled, and the Decepticons make tracks, claiming that this victory is but a small one in a greater war. Optimus returns to his troops to aid them in rebuilding the Autobots' headquarters so that they can prepare for the next Decepticon attack.
Transformers Prime: Decepticon Strike is a top-down view third person shooter game. The player clicks and drags Optimus Prime across the screen as the terrain scrolls forwards. Optimus's weapons are constantly firing, allowing the player to concentrate on dodging enemy fire and destroying enemy units. The Autobot leader alternates between his robot, vehicle, and flight mode throughout each level, and is pitted against a slew of Vehicons before facing off against the "boss" at the end of each level. The number of Vehicons and the frequency of their attacks increases with each level, as they weave across the screen in an array of patterns. The final enemy at the end of each level faces off against Optimus in either aerial or ground combat, and retreats once their health bar has been depleted, completing the level. If Optimus Prime's own health bar is depleted, the whole level must been done over from the beginning.
Throughout the level are power-ups to help Optimus along the way. "Attack" power-ups increase the potency of his firepower for a short time, "Health" power-ups replenish his health bar, "Shield" power-ups temporarilly enclose Optimus in a forcefield from where he can shoot his opponents but they cannot damage him back, and "Bomb" power-ups give access to a weapon that can clear the screen of all enemy units, save boss units.
In between each level, the energon that Optimus collects from fallen foes can be spent as currency to permanently upgrade the size Optimus's health bar, his resilience to damage, or the damage dealth by his shots. Each stat can be upgraded three times before it is "maxed out."
Optimus cannot attack in vehicle mode, but is much faster in this form than in his robot mode.
- Optimus Prime
- Vehicons/Jet Vehicons
- Dreadwing (Level 1)
- Knockout (Level 2)
- Breakdown (Level 3 and 8)
- Airachnid (Level 4 and 8)
- Shockwave (Level 5 and 8)
- Starscream (Level 6)
- Soundwave (Level 7)
- Laserbeak (Level 7)
- Megatron (Level 8)
- Alpha Trion and Smokescreen make brief cameos in the expository sideshow at the beginning of the game, but do not take part in the game itself.
- The music playing in the game's title, menu, and upgrade screen is "Arrival to Earth" from the 2007 Transformers film's score.