My Ape Escape 2 guide containing general tips.

Obscure Techniques

• R1+R2 while running causes you to dive forward. You begin by arcing through the air, making you liable to fly right over your target before you land. It’s really hard to aim this move, and it might be better for dodging attacks than for making your own.
• Jumping and pressing L3 has you ground-pound. It’s an extremely slow attack and not great for hitting anything that moves around, like Monkeys. The real value of this technique, if any, is not having to equip an attack Gadget like the Stun Baton to kill enemies.
• When moving horizontally, short hops are much faster than full double jumps. This is especially relevant for falling platforms and bridges, etc.

Time Trials

• I recommend not doing Time Trials until after seeing the credits. Having all Gadgets greatly opens up your potential paths through a level, and some time benchmarks seem designed for you to be able to reach certain Monkeys immediately. It’s entirely possible to get almost all Gold times the moment they’re available; there’s just no reason to. You risk spending more time via failed attempts, or having to come to the realization that you need more Gadgets.
• The Super Hoop makes you move faster, so it’s obviously essential for Time Trials. Ideally, you’re already rotating the analog stick by the time the starting countdown ends, allowing you to immediately blast forward. The problem is that the game defaults to the Gadget assigned to the X button, then, if applicable, whatever Gadget you last had equipped. If retrying a stage, for instance, equip the Super Hoop before leaving. That way, you don’t need to lose time equipping it at the start of your next attempt.
• Be smart while using the Super Hoop. The time saved by moving quickly has to be equal to or greater than the time spent charging the Hoop up, or you’re losing time by using it. This means that you shouldn’t use the Hoop for short distances where you might need to jump etc. before you compensate for the Hoop’s charge time. Don’t just spam the Hoop for no reason.
• The game can be finnicky about collision with the Hoop. Some stairs are low enough to run over, while others will have you bonking against the steps, resulting in significant time loss. You can kind of get a feel for what’s permissible, but sometimes, you’ll have to learn via trial and error.
• The Sky Flyer is another useful Gadget for potentially allowing you to skip parts of levels. This is more common in stages taking place before you normally obtain the Sky Flyer, as distances weren’t created with the Sky Flyer in mind. Still, it can always come up, so keep it in the back of your mind.

Bosses

• Also helpful to know for Time Trials, bosses can be damaged outside of their standard vulnerability times. If the boss flashes after being hit, they took damage. A red flash simply means you did extra damage by hitting it at a vulnerable time.
• The two Gadgets most capable of hurting bosses outside of their normal weak points are the Slingback Shooter and Magic Punch. The Magic Punch is pretty simple, since it’s practically a powered-up Stun Baton. The Slingback Shooter requires you to use Explosive Pellets, which have limited ammo. You can increase your maximum ammo for special Pellets through Gotcha Box rewards.
• If you’re aggressive with using these Gadgets against bosses, you can kill them quickly enough to skip entire phases of the fight and trivialize Gold Time Trial times. Bosses don’t seem designed with the expectation that you’d fight them this way.

Bonus RC Cars

• It’s possible to get extra RC Car models from the Gotcha Box after reaching certain stages. These don’t just look different; they play differently, too. Their speeds vary, and they sometimes have special attributes. The Pudding (flan) RC Car has a larger explosion when struck, for example.

Minigames

• Like RC Cars, Minigames can be obtained from the Gotcha Box after clearing specific stages.
• I have to admit, I find the minigames in Ape Escape 2 to be pretty goddamn difficult and frustrating. I’ve yet to make enough progress with any to provide useful advice. The developers seem to have gotten their sadistic predilections satisfied through the minigames.