Namco tries to squeeze as much of the AC formula as they can onto a UMD. And for the most part they are successful.
In ACX you are a fighter pilot fighting to free your country of Aurelia from the occupying forces of Lesath. The Lesath leader has taken over your country and immediately began the manufacturing of terrible new weapons. You and the remaining Aurelian forces must roust them and put a stop to their weapons' development.
The gameplay in ACX is what you would expect form an AC game. If you have not played an AC game before, it is fast-paced air combat that falls somewhere in the middle of arcade action and simulation. You fly a miriad of real world and fictional aircraft and engage air, land, and sea targets, and come up against some terrible fictional weapons as well. All of the facets of AC combat, except the wingman commands from the last two PS2 games, are intact. The new addition to ACX is the ability to "tune" the fictional aircraft with parts you aquire in the hanger. These include engins, wings, armor, and more. It is a good system, but some of the parts are not very useful because they have too big a cost on the performance of your aircraft to justify the benifit they provide. Still this system is implemented well and I hope it will be included in future AC games with a little refinement. The only real gripe I have with the gameplay is that it is more difficult on the PSP to discern my altitude just by looking at the ground than it is on the PS2 because of the smaller screen. This lead to more crashes than I have experienced in previous AC games. But once you get the hang of checking your altimeter more often it is not a problem. I also wish the PSP had a second analog stick so I could check my surroundings with out turning my aircraft, like in the PS2 versions, but this also is not a major problem.
AC has always been known for the qulaity of its model and environmental graphics. And ACX gives a very solid impression. Obviously the PSP does not have quite as much horsepower as the PS2, and the UMD does not have as much storage space as a DVD, so some concessions had to be made. That being said the developers have put together a great looking game, that captures the spirit and look of AC. The plane models are great as always, although some of them are not quite as animated as they have been on the PS2. The environments are where the PSP noticably lags behind the PS2. They are more than respectable but they lack the detail the PS2 versions had, and the draw distance is also a bit shorter than it has been in the past. All in all I think the AC team at Namco did a great job of fitting as much of the look of AC as they could onto a UMD. It is also worth mentioning that the story sequences are shown through the use of hand drawn images like in AC4, which is one of the things I really enjoyed about, and have missed since, that game.
The sound quality is just as good as it has ever been in AC. Get yourself a good pair of head phones to really appreciate it. The music is also good, but the music selection did not seem as inspired as it has on previous AC games.
This game is currently priced the same as any other PSP game that is not a greatest hits/platnium title. This game has only 18 missions which is a bit short when compared to previous AC games. There is a free mission mode that lets you play any mission on any difficulty with any plane you currently own. There is also four player online play via adhoc. There is however no arcade mode, the inclusion of which has lended longevity to previous AC games. I would say this is a good buy for any AC fan, or anyone who enjoys air combat and owns a PSP.
All things considered Namco has done a great job bringing AC to the PSP. I hope they will make more AC games for this system, and I know that if they do they will find ways to improve where this game slightly lags behind other iterations of AC.