There hasn't been a Jak and Daxter game for ages. After the duo made such an impressive debut on the PS2 back in 2001, the series dropped the "and Daxter" part of the title, went darker and placed a larger emphasis on using guns. Developer High Impact Games, the team responsible for the PSP Ratchet and Clank games, has taken over the reins from Naughty Dog, picked up after the events of Jak 3, and put Daxter back in the title. The result is Jak and Daxter: The Lost Frontier, the studio's best PSP game to date.
I don't think I've ever fully understood the plot of the Jak (and Daxter) games, but it's all got something to do with Eco; goo found in numerous colours that has the power to do wonderful things. In this PSP adventure our duo are involved with Sky Pirates, meaning much of the game is spent roaming the skies and then landing on islands below to continue your journey on foot. The two distinct styles work well together and give this PSP game an identity of its own.
In The Lost Frontier, Eco grants Jak new abilities essential to making it through the game's many platforming and puzzle challenges. Red Eco, for example, lets you fire off a ball of energy that can be shot and detonated, causing a great deal of damage to enemies and breakable objects. Yellow Eco lets Jak use a rocket hover jump, letting him reach high platforms, and there are more to discover.
Early levels don't ask much of you, more or less making it obvious which Eco power is needed, but things do become more interesting and challenging as you progress through the story. You'll eventually need to use a combination of powers, and while it's never taxing to the degree that your brain hurts, it's enough to make you feel smarter than you were a few moments earlier. Eco can also be used to purchase new moves and enhanced abilities, giving Jak more options while fighting off enemies.
The Lost Frontier, like its series predecessors, features a mix of platforming and combat - both melee and projectile-based. Jak is pretty nimble, able to jump from platform to platform, clamber up onto ledges, swing across beams and generally navigate through each of the diverse locations with ease. He's also quite nifty with his fists and doesn't shy away from guns. Melee attacks are fairly basic, but there is a combo system for more advanced moves - not that this ever reaches true hack 'n' slash levels.
Gunplay comes from the modifiable and upgradeable Gunstaff. If you want more brute force, switch to the shotgun-type mode, while more mindless firing can be achieved with the machine gun add-on. The game never reaches the heights of the weapon upgrades system and diversity found in the Ratchet and Clank games, but it's certainly a neat mechanic.