Trenched is a book you really can't judge from its cover. What appears to be one thing on the surface actually mashes up several game genres to create something that looks good, plays good, and feels good. Like anything you'll play, Trenched is hardly perfect, but it does a great job presenting a strong visual front and well-polished package. Basically, it presents much like a mech-based fighting/shooting game. You view the world in an over-the-shoulder, third person perspective, controlling the camera and movement as you would in any typical action game. Unlike free-roaming games, there is a relatively small area you can move around in Trenched. This is really a defense game masquerading as an action title, but it doesn't lose much in translation. Fans of RTS or Tower Defense will actually see all the familiar elements of those genres here, buried in the Trenched plumbing. Whether they'll tolerate the radical change in perspective and the more active controls is an open question, but Trenched plays the action gaming cards well. Not only are the graphics slick, but there are some great visceral sound effects and smart dialogue to accompany the action. This is a war game, after all, and it delivers nicely on the sound and fury of being caught up in a heated battle. When you're not fighting, the interface is a bit heavy on menus and icons that come with a learning curve, but this is where Trenched skews more toward strategy gaming elements. Action fans will just need to adjust a bit...

This talk of mashup may not make much sense, because we honestly haven't seen many games like Trenched before. Imagine you could play as one of the many units you move around during an RTS game. Imagine you could combine the raw action of a mecha game with the intelligent strategy of Tower Defense. These are the elements that are combined in Trenched, and it really works. The premise is that humankind is engaged in a battle, with traditional forces massed against a mad scientist intent on uploading people into electronic vessels. The enemy uses units that appear as various kinds of technological nightmares, bristling with wires and crackling with electricity. In every level, you'll need to defend against the advance of these creatures by using your own brand of technology.

The Trenched title comes from a unique concept of soldiers taking trenches with them, in the form of giant walking trenches. It's a mecha concept really, with the soldier riding what appears to be a giant chassis adorned in WWII style, complete with sandbagged trench. The retro theme runs throughout, but the gameplay is very similar to something like Armored Core, with upgrades to your unit and new enemy units. The great twist is that Trenched supports up to four players, each bringing in a unit and fighting off enemies through online or local co-op. The potential for this as a party game is low, because there's some level of complexity in learning the interface. Games like Trenched show the way for online multiplayer to break out of its rut, to get beyond the usual suspects of racing, sports, and fighting games. A thinking-man's online gameplay is a welcome diversion for those of us that aren't interested in fragfests or reliving Sunday's ballgame on Xbox LIVE. The depth of multiplayer in Trenched also increases replay value considerably.

Learning any new style of game is a bit tricky, both in terms of controls and gameplay. Starting with gameplay, Trenched goes easy on you for a few levels, before dispelling any notion that you can play the game like an action title. The classic model for a strategy game is that you aren't doing anything directly, just acting through agents. Tower Defense takes human actors out of the picture but maintains that you won't take direction action against enemies. Trenched is really the same kind of game, but you do have the opportunity to mix it up and take out enemies yourself. Unlike classic action games, where a sufficient amount of button-mashing will almost always return great results, Trenched forces you to think about defense. You collect points by defeating enemies, and you use those points to buy emplacements. Each emplacement works best against certain types of enemies, which means you really have to learn the progression of waves and the attack styles of enemies. The controls are relatively simple once you've mastered these concepts, but you'll have to master the transition between running-and-gunning (still possible here) and skillful placement of defenses. If you aren't timely in these ways, you'll eat it frequently in Trenched. Once you get the feel for your strengths and enemy weaknesses, the game's difficulty is tamed a bit, but it definitely presents a good challenge. Bring a friend...

Probably the worst moments of Trenched are spent navigating menus and outfitting your "trench." Fans of games like Armored Core won't bat an eyelash at this stuff, but it feels like major overkill to those of us who like to get straight into the action. It's a necessary evil, because you won't accomplish much without a fitted-out rig. Not only is it important to customize the weapons installed on your trench, but you also need to pick the emplacements carried into each level. If there are going to be lots of aerial enemies, you'd better pack flack weapons. Some opposing units aren't vulnerable to specific weapons, so you need to consider smart combinations. It's a trial-and-error process, but you do get better at reading and anticipating the upcoming squads. Depending on which type of territory you're defending, the choice of mecha will also be a factor.

We'd love to say that Trenched is an acquired taste, but it's probably more polarizing than that. If you can find your way through the mashing up of at least two genres here, you'll find a really cool game that plays just as well for one player as it does with four. It's rare to find this at all, but the notion of a co-op RTS game is just too cool to pass up. If you like RTS or Tower Defense, be aware that you're going to have to get comfortable with a bit more camera and movement than you're used to. At the end of the rainbow is a game that packs the humor and polish you'd expect from Double Fine, and truly does something different. If only for this reason, it's well worth a look.