Armored Core: Formula Front. I was honestly surprised when I started playing this. Despite being a handheld entry to the venerable series, the quality of the game is equal if not better to it's console brethren.

Graphics:
The graphics are about on par with the PS2's Armored Core 2. The resolution and texture for the landscape, buildings, etc., are very low-key and bland. However, the mecha themselves are very highly detailed, and the gunfire, lasers, missiles, and explosions are very enjoyable. The frame-rate is very high also.

Controls:
The controls about as good as the PSP's control scheme allows for, which has always been a bit deficient due to the lack of a second thumbstick. There are two modes of control: Manual and AI. Manual uses a very standard Armored Core control scheme that can be customized. AI mode is where the Computer controls the mech, and the PSP controls make for a very good cinematic camera scheme. More on AI mode later.

Gameplay:
This game shines in two areas.
The first is the level of sheer parts customization. There are hundreds of parts, for every single part of the mecha's body. There are also many weapons, and performance enhancing add-ons. Many parts can also be "tuned", reducing weight, adding more armor, or draining less energy.
It's also worth noting that there is no money system for purchasing parts. Every single part is unlocked at the beginning of the game, and ammo and repairs are free. This means you don't have to wait and save up to build that heavily-armed superweapon of a robot.

The AI is what really sells this game. The artificial intelligence of each of Mecha can be programmed down to a very minute level. You can program it to stay at long range or short, how aggressive or defensive it should be, how much to jump around or dash, and how often to switch it's weapons. You can also allocate a set number of point to improve it's mobility, target acquisition, terrain navigation, weapons handling, energy consumption, etc.

Lastly, you can install "performance chips", which tell it what do at specific points in the battle. For example: I may create a close-range mech with long-range missile launchers, as well as a short-range laser blade and shotgun. I can install a chip ordering my mech to focus on using missiles in the first 30 seconds, decimating the enemy before moving into closer for the other weapons.

All in all, this is a great game, and I highly recommend it to Armored Core fans.

I picked up this game a few days ago on the hope that the AI customization would allow for direct programming of the AI routines. For example: jump/fly forward 15 feet, scan, if enemy found: shoot, etc. Similar to Origin's Omega circa 1987.
Actually, such AI programming is more suited to 2D enviroments than 3D, so I am not disappointed. What you get instead is a small set of routines you get to unlock, and a bunch of combat style variables. The selling point for others, I suppose, is the ability to use 300 or so components to construct your uber-AC and combat other such constructs either manually (with the US edition) or in simulation. I have learned that the game is seriously unballanced in this respect. There is the possibility to construct an AC which is so stupidly powerful, that anyone who has less than a modicum of an idea what they are doing (such as myself) will simply be obliterated within 15 seconds. The challenge then becomes, ignoring the point of numerous failures, what exactly is his weakness? Well, he's slow and heats up fast. You can't get him by direct attacking. Too tough. You can't get him by flying about, he'll just shoot you down. And if you try long distance sniping, the arena is too small, he just has to get into range. So all I can think of is to try to stay out of his vision, and wait until he breaks down from overheating after 2/3 of the match is over. This game requires some difficult planning. I think the game should have allowed for some form of direct AI programming in order to deal with this issue and to the circumvent the need to find the right tactical combination of routines through tedious trial and error. But I did buy the game expecting this.