Archer Maclean’s Mercury is not your typical Tetris or Lumines type of puzzle game. It's more of a straight up test of hand-eye coordination, problem solving and logic. The premise itself is easy to grasp though; using the PSP's analog stick, "tilt" a floating 3D maze to maneuver around blobs of mercury, with various switches, platforms, obstacles, and hazards standing between level goals. The goals to be accomplished in the various levels are fairly simple and usually involve activating 1 to 6 "beacons". How these goals are actually accomplished is what makes the game so interesting. Dealing with the liquid metal as it bends and melds around everything is quite a bit different than controlling or predicting the motion of a solid ball. The physics model incorporated into the game is definitely impressive, and witnessing the oozing, reflective blob respond to your subtle movements of the maze is pretty unreal. Like a real piece of mercury, the seemingly solid-looking globs can smoothly glide around a surface while exhibiting all the qualities and physics of a drop of liquid. This leads to a number of interesting obstacles and hazards which can cause your blob to be shattered into many little mercury bloblets, sucked up and piped around, zapped or eaten up, or fall and ooze off the edge of the maze into oblivion.

The 72 maze levels are broken into a number of well-designed, elemental/location themed stages, like Neon, Quartz, Xero, Aqua, etc. These stages are further divided into 4 different stage types: Race, Percentage, Combo and Boss. The types are pretty self-explanatory; Race requires you to get any piece of your mercury to the end goal in as short of a time as possible. Percentage requires you maintain a certain percent of the blob until you accomplish the stage goals. And combo mixes both of those stage types. The Boss level, which is unlocked after the rest of the stage is completed, is usually a much more complicated and lengthy Combo stage. Beating that will unlock the next themed stage, and so on.

Besides simply navigating from point A to point B in these maze-like environments, a number of the beacons and gates can only be activated or utilized if your mercury is tinted with the right color, or if you have enough volume to trigger a certain switch. Control is the name of the game, and just one subtle mistake can cause you to lose all of your mercury blob, or at least enough of it to cause a level failure. If you do split up your blob in an unwanted way, you'll have to find a solution to reunite as many of the pieces as you can. Because the entire level is tilted at once, all the pieces move along the maze simultaneously in whichever direction you move it. In many of those cases, you will have to find a way to trap the mini-blobs you need in such a way where you can eventually stick them back together. Some stages actually require you work with multiple blobs (sometimes of different colors as well) at the same time in order to solve the level. In those instances you are usually fighting to keep them apart as to not alter the size or tinting of either piece.

The stages and mazes in Mercury start out fairly easy, but about 2/3 of the way through they become devilishly difficult. The game offers hints for the first set of levels but after that it’s up to you to find the solution. Most are obvious, though one or two will definitely have you scratching your head in confusion. Completing all the levels in the game will only take a few days, and afterwards all that’s left is to perfect your strategy and beat some of the developer’s high scores for each maze. There is a 2 player local WiFi mode which requires a copy of the game for each PSP, but as of this review, we were not able to give it a try.

Gameplay requires the use of the PSP's little analog pad. I have been exclusively using the digital pad on most of the PSP games I've been playing, that is, until Mercury. The level of control exhibited with the pad is excellent, and the game will definitely help you appreciate that fact. If this game does nothing else for you, it will at least make you an expert at using the analog pad. A lot of the levels require pinpoint accuracy and movement to successfully navigate your mercurial glob around the mazes. It's actually not that much of a struggle, at least in regards to the actual gameplay control. The camera, on the other hand, is somewhat off. It is full adjustable (freely or in increments), but it starts a bit too zoomed-in and tilted for my taste. So before I even move the mercury, I zoom out and flatten the view. There are also a small percentage of the stages that feature structures over structures which can easily obscure the camera, and because you are always racing against the time in one way or another, rotating and zooming the view can be a costly option.

Graphically, the game is colorful and pleasant to look at. The 3D stages and backgrounds are detailed enough to be interesting, but not to the point of being a major distraction. The mercury, and especially how it moves, is the real star of the show. They way the developers were able to replicate the smooth fluid-like motion of the mercury blobs, not to mention the physics in how they react to environment, is very impressive. The menus and things are generally stylish and above average as well.

The audio does a good job in keeping your ears busy, with some mellow background tunes and decent enough sounds effects. I liked the little liquidly “bloop” noises that your mercury makes while oozing and bouncing about the stages, and the falling effect when dropping off the edge of the maze.

For a handheld system, the PSP doesn’t have all that many puzzlers available yet. Lumines is the obvious killer app but Archer Maclean’s Mercury also does a great job in providing an interesting new twist to the genre, at least for as long as it lasts. It doesn’t really have the endless appeal of something like Lumines, Puyo Pop or Tetris, but the problem solving, logical puzzles and interesting physics make it nonetheless enjoyable.