Jak and Daxter: The Lost Frontier is a platform game developed by High Impact Games published by Sony Computer Entertainment. It is a part of Naughty Dog's Jak and Daxter series, and was released on November 3, 2009 for the PlayStation Portable and PlayStation 2. The player assumes the role of Jak, the angst-ridden hero enhanced by his exposure to Light and Dark eco. The game was released to favourable reviews, with critics praising the graphics, gameplay and aerial fights, but criticizing the bad camera angles and its bland and repetitive ground fights.
Jak and his sidekick Daxter, begin the game escorting Keira on her journey to become a Sage and help to find the reason for a worldwide Eco shortage. After an encounter with Captain Phoenix, an Eco-seeking Sky Pirate, Jak crash-lands on an island at the Brink (the edge of their world) and sets off in search of Eco with which to repair his Hellcat. After a successful take-off, Jak must fight off Sky Pirates attacking the ACS Behemoth, an Aerial Warship captained by Duke Skyheed of Aeropa. Jak is given an instrument called the Eco Seeker. He is unable to power it because the excess Dark Eco in the area prevents him from using his own Eco powers (he is also unable to become Dark Jak because of the Eco instability), but Keira is granted permission to study it for a week if Jak proves himself in a test of his fighting skills. Daxter falls into the underground of Aeropa on the way back, where he becomes tainted further by Dark Eco and is temporarily transformed into "Dark Daxter".
Then, Captain Phoenix attacks the building and steals both the Eco Seeker and Keira. Jak and Daxter chase Phoenix but are led into a trap, resulting in them crash-landing back on the Island again. On the Island the duo meet the Castaway, who knows that Jak has been touched by Dark Eco, but can't remember his own name, nor why he was on the island in the first place. He also mentions that he built the robots that occupy the surrounding area. He also offers to fix Jak's Hellcat, but requires a Power Pod from the most dangerous robot the Castaway ever created. After Jak and Daxter get the Power Pod, the Castaway fixes his ship and later sneaks on board. When Jak and Daxter take off they manage to disable Phoenix's ship and land. On board Jak and Phoenix argue and tip the Eco Seeker overboard accidentally, so both return to the island once more to retrieve it from a volcanic crater.
The Eco Seeker needs more Light Eco to work and they travel to an old research rig used by the Aeropans. At the rig, Jak comes across a testing table (similar to the one he was experimented on in Jak II). He realizes that someone has been experimenting with Dark Eco and vows that whoever did it should be destroyed. After finding the Light Eco, Daxter is again exposed to Dark Eco and is briefly turned into Dark Daxter again.
After the Light Eco is inserted into the Seeker, Jak finds out that it is missing three parts, and they travel to the pirate town Fardrop to get the first piece from a pirate. When they travel to an Old Aeropan Barracks, where they find one of the Coordinates, the Castaway reveals that he is (or once was) a Dark Eco Sage, that he built the facility for the Aeropans and he built the Brink Island robots to try to undo what he'd done. Phoenix reveals that he was once the commander of the Aeropan Air Forces. He was put in charge of a secret weapons program to make a new kind warrior (similar to the project that gave Jak his dark powers). When he found out what they were doing, he refused and tried to stop the program, but Skyheed wouldn't hear of it. So, he took the only option left and kidnapped the program's chief scientist, the Castaway. In the scuffle, the Castaway took a blow to his head and suffered amnesia. He was marooned on Brink Island to hide his work from the Aeropans ("Too little, too late!" Jak states). Phoenix further explains that Skyheed spread the dark power to all the Aeropans, who then declared Phoenix an outlaw and in return, he vowed to destroy all dark warriors, including Jak. Keira protests, saying that Jak isn't a monster, and she gives Phoenix an ultimatum that if he cared for her at all, he would spare Jak. The Castaway then says that Jak can be used to undo the damage done, being "a warrior who proves Dark Eco can be controlled, or at least managed". So Jak agrees with Phoenix to take out the Aeropans.
When the location of the third coordinate sphere is found, the duo fly to a mysterious location beyond the edge of the world. Jak and Daxter get the third sphere, but the Behemoth attacks their ship and Jak has to defend it. Back on board, Jak, Daxter, Keira, Phoenix and the crew fix the Eco Seeker, which points to the abandoned research rig. Phoenix recalls that the rig was built over strange formations, later revealed to be an ancient Precursor facility. When they reach the Eco Core, Keira tries to fix it. Shortly after, Phoenix's right hand man, Klout, arrives with Skyheed and reveals he was paid off by Skyheed in exchange for the location of the Core. Skyheed orders everyone killed except Jak, because he wants to study his control over Dark Eco. However, Keira activates an energy dischagre from the Eco Core, which kills Klout and stuns Skyheed while Jak, Daxter, Keira, and Phoenix escape.
Back on board ship, they receive a message stating that the Aeropans have laid siege to Far Drop. Jak and Daxter are sent to defeat the Aeropan forces, but the Behemoth appears to level the town. Jak and Daxter successfully destroy the Behemoth's weapons, causing the Aeropans to retreat. On board the Phantom Blade, Phoenix wants revenge on Skyheed for the attack. Then another message is transmitted anonymously, telling them to use the old Barracks warp gate. Jak, Daxter (who gains the ability to turn into Dark Daxter at will following being seized by an Aeropan soldier), and Keira get through the warp gate and Jak's Gunstaff weapons are disabled. Jak has to destroy the Weapons Control System to get them to work again, then head up to the palace to defeat Skyheed. But when Jak encounters Duke Skyheed, Skyheed begins absorbing massive amounts of Dark Eco which transform him into a giant monster. Jak tries to defeat him but Skyheed escapes on an Airship. Skyheed retreats to the Behemoth, intending on using the Eco Core's power to take control of the planet.
Jak then has to stop the Behemoth from absorbing the power from the core. The Phantom Blade disables the shields surrounding the Behemoth, while Jak destroys the weapon systems. Phoenix eventually flies the Phantom Blade between the Eco Core and Behemoth to prevent them from using the Eco, sacrificing himself in the process. Cutting off the Eco flow leaves the Behemoth vulnerable to attacks. A forlorn Keira then installs a Light Eco Beam in the Hellcat to finish the Behemoth off.
When Duke Skyheed and the Behemoth are finally destroyed, the balance of Eco is restored. Keira then activates the Eco Core which channels energy which travels to Eco Vents around the world, ending the Eco shortage. In the process, Keira finds she is now able to channel Eco, with Tym (the Castaway) informing her that she may be turning into a Sage. She also sees that one vent flows out beyond the Brink and she, Jak and Daxter decide to investigate.