Providing you weren't born a teenager, it's a safe bet to assume that you have, at some point in your childhood, pretended to be an aeroplane. It sounds stupid now, but at the time it was a leap of imagination, an almost-literal flight of fancy.

Regrettably, times change, and we change with them. Aeroplanes become less about leather jackets and a highway to the danger zone; more about seatbelts and the aisleway to a grumpy stewardess. Less Tom Cruise shooting bogeys out of the sky and more Tom Cruise flicking bogeys onto the carpet of our easily-influenced youth. The problem, you see, is we grew up and faced our reality: the closest we'll ever get to dogfighting is throwing a dog down the stairs.

So when we say the best thing about Ace Combat X is that it makes you feel like a child again, we honestly mean it in the best possible way.

Which isn't to say it's childish – on the contrary, the game takes itself pretty seriously. In a desperate attempt to reclaim your country from the grasp of the neighbouring nation of Leasath, it's your job to work your way through 15 gorgeous-looking battlefields, destroying all who oppose the uprising.

Oddly, it's not on the battlefield that Ace Combat X's tactical depth shines through, but rather, on the map screen. Often, you'll be given an important mission – usually taking back a crucial strategic point or city – and how you get there, through several intermediate sorties, is up to you.

Depending on the order in which you attempt them, the objectives in the battle zones change completely. What this means is that, on your first play-through, you'll only have flown half of the available missions, even though you may have visited every battle zone. Not only that, due to the layout of these intermediate stages, it's not necessary to do them all to reach the final big battle. Although each one completed will give some sort of benefit, if a mission proves too difficult you can just take one of the other paths, circumventing the problem of ever becoming stuck.

The missions themselves vary in quality, but that's mostly because a handful of them are so white-knuckle and imaginative that, in comparison, the others can appear dull. An early assault on an aerial fortress is a prime example: it plays out so brilliantly that, when the game fails to better it, it's easy to feel disappointed. Nevertheless, none of the missions are ever boring, unfair or overly difficult. It may not be a turbulence-free ride even on the Normal difficulty setting, but thanks to quick restarts you'll rarely resent having to retry a mission.

In fact, it's something you'll frequently do deliberately. Mission performance affects the amount of money received, which is used to spend on new aircraft, weapons and customisation parts. So if you want the better aircraft you'll often have to replay missions to earn more credits – which may sound like a chore, but seldom feels like it.

With over 30 missions, 40 aircraft, 120 weapons and a huge array of parts, Ace Combat X is a staggeringly vast game (and that's before mentioning the fully-featured ad hoc multiplayer mode). Both in its scope and execution it's almost a PS2 game – the graphics are frequently surprising in their detail and there's not a single piece of text that doesn't have a voice-over. That such a massive experience has been crammed into the PSP is yet another testament to Namco's technical mastery of the format.

That's not to say there's no downsides: the load times can be a little long, the lack of urban missions is regrettable and a strange grain effect occasionally spoils the visuals. Perhaps most disappointingly, the story – although given a significant part of screen time – ends up being far less thrilling and slightly shorter than anticipated.

But the fact these feel like minor gripes is telling, because ultimately it's hard to come up with any major problems. The whole experience is every bit as thrilling as your childhood's self-imagined dogfighting, leaving a mark upon much of the PSP software library like a lingering jet trail on a clear summer's sky.