If you're looking for a good, fun-spirited platformer on the PSP, look no further.
The story is pretty basic. A monkey named Spector gets hold of a white helmet turning him into an evil super genius plotting to replace mankind with primates. On his way, he sets free a variety of monkeys which causes mischief and mayhem in whatever time period they travel to. Our young hero is a boy named Spike who travels back in time to stop those monkeys from changing the future.
Worlds are based around different time periods and are accompanied with a set of levels to capture monkeys in. For instance, your first destination in the game is the Prehistoric era. In each of the levels, your primary goal is to capture all the monkeys scattered around the area using the various gadgets handed to you throughout the course of the game. You start out with your basic net and stun club, both of which are necessary to rid the vile primates from each time period. As you progress, you'll receive even more gadgets to help with your quest. Because of this, monkeys in past levels which seemed un-catchable are once again in your grasp. Some of the other gadgets include a monkey radar, useful to scout the area out; the hula-hoop, necessary for travelling at high speed; and the sling-shot, handy to defeat any airborne creatures blocking your path.
The game looks inherently better than its original. In fact the game world looks strikingly reminiscent to Ape Escape 2 for the PS2. The time periods Spike travels to has its own unique charm and image, giving the game a colorful look. However, some enemies tend to look particularly hideous. The frame-rate occasionally dips down on some of the larger levels, but it's not a major concern. The sound is done well in the cutesy sense -- monkeys squeak and make noises only monkeys can generate and enemies pop when defeated.
However, controlling Spike isn't quite as well done. Originally, the right analog stick was used to control Spike's various gadgets. However, since the PSP is without a right-analog stick, using gadgets has been altered a little bit. Now your three gadget buttons are pressed to both use and equip a gadget. It's a little awkward at first and definitely takes some getting used to for Ape Escape veterans. The camera is also a hassle, and is altered by pressing the L button to center or the D-pad to pan the camera around manually.
If you get bored of Spike's quest, a variety of mini-games may help rid you of that boredom. With a friend, you can accomplish all your wishes and dreams by beating up monkeys in Monkey Boxing, shredding the slopes in Monkey Snowboarding, and even playing ping-pong with some of those feisty primates.
Overall, Ape Escape: On the Loose is a fun, engaging title for the PSP. It certainly could've been better and if you get the opportunity, play the PS1 version instead. However, if you're just looking for a good, fun-spirited platformer for your PSP, look no further.