While sleeping near the Grand Canyon, a mosquito-like drone sucks most of the DNA of Ben’s Omnitrix. A giant object crashes into the mountains, and Ben finds out he can’t transform into some of his aliens, only Heatblast and Four Arms. After fighting through multiple drones, he defeats a Giant Mech Drone and finds an Omnitrix Crystal which gives him access to XLR8.
Later, they go to Mesa Verde and find Vilgax’s Drones and Forever Knights fighting. After defeating all the knights and drones, the Tennysons ask an injured Forever Knight about Enoch. He says that Enoch has used all the Technology of Area 51 to make a Big Battlebot to fight Ben. They go to Area 51 and fight Enoch, but Enoch recovers and climbs his battlebot. They think of some hydro-electric place where the Battle Bot is comfortable to fight, and Gwen thinks it is Hoover Dam. They head to Hoover Dam and fight the Battle-Bot. Then Ben finds another Omnitrix Crystal which regains access to Cannonbolt.
When the Tennysons head to San Francisco for a vacation, they fjnd out that Kevin 11 has escaped from the Null Void and has brought some plant creatures with him. He kidnaps Grandpa Max and gets sucked to the Null Void again by Ben in the Lumber Mill. Later, after fighting through Crater Lake, they head to Seattle, where the mother plant (Wildvine’s DNA) has made its home and infecting the whole city. After defeating it, Ben finds an Omnitrix Crystal which gives him access to the Last Unlockable Alien in this game, Wildvine.
In outer space, Vilgax and Zs’Skayr are working together to recover the Omnitrix. Ben, Gwen and Grandpa Max head to Effigy Mounds for camping, and find some of Zs’Skayr’s Troops hunting there. After defeating Hex at the end, they discover than Zs’Skayr is the one behind all this. He also had plundered the Plumber Base. Ben defeats him in Gold Coast Theater and Grandpa Max sucks him in the Null Void. Ben then unlocks Master Control in the Omnitrix.
After defeating Zs’Skayr, in the Historic Battlefield, Dr Animo had kidnapped Gwen. They go to Bayou and discover that Clancy, (One of Ben’s other bug villians) had camped inside a Cave. After Ben defeats him, Max asks him where Animo had taken Gwen. He tells him that it is too late to save her now and Animo will make her a mixed-up mutant. After defeating Animo, Gwen tells them that Animo and Vilgax have planned to suck Earth into the Null Void.
After going to Washington DC, where there are Null Void Portals everywhere, Ben defeats Sixsix and his Detrovite Troops in Cape Canaveral. Grandpa Max uses a rocket to make the Rustbucket capable of flight. Then, they fly to Vilgax’s Ship and Ben tries to defeat Vilgax. After a big battle, Ben discovers that rest of the Omnitrix Crystals are right there in the ship. But just after touching them, the ship starts powering down and projects a Null Void Portal in front of the ship, and Vilgax and his ship get sucked into Null Void. Luckily, Ben, Gwen and Grandpa Max escape in time.
In the beginning, Ben can stay an alien for a limited amount of time, but after defeating some bosses, Ben unlocks more powers for his aliens and even unlocks the master control, meaning he can stay alien for an infinite amount of time or switch between aliens without draining Omnitrix energy. Attack combos can be unlocked collecting Omnitrix points. Limited power boosts or invincibility can be gathered, as well as bonuses to make the Omnitrix recharge faster. Three Sumo Slammer cards are hidden in each main level, and once collected unlock features, such as movie clips.
After each level, Plumber ranks are rewarded, depending on how fast the player beats that level. If the player gets an A rank, you get a character view, usually a boss or a villain. In the main boss levels, a quick time event similar to those of God of War allows players to execute a special attack at certain points.
Critical reception has been mainly average. IGN awarded 6.8 out of 10, commenting that the cel-shaded graphics, simple gameplay and on-the-fly saving suits the target demographic but was unable to recommend it for hardcore gamers. Eurogamer gave 5 out of 10, highlighting the drop-in drop-out two player mode and decent cutscenes, but criticising the bland environments.
Gold Coast Theater