Trenches is a fun and challenging World War I-themed trench-warfare arcade game with strong elements of real-time strategy and unit and resource management.
With its killer combination of winning art direction, well-designed gameplay, and a shallow but steady learning curve, Trenches is hard to put down. You control British troops advancing from trench to trench, left to right, across a long, scrolling map (which you can tilt to scroll, or touch and drag the skyline to move). You touch and drag units to determine their path, and you can use a two-finger motion to direct all onscreen units to retreat, advance, or hold.
A relatively short campaign mode reveals the game's unit types one by one, letting you choose which you want to add to your arsenal, from basic riflemen on up to engineers, snipers, machine-gunners, and mortar crews, each with its own advantages and disadvantages (and each capable of improving if you can keep it alive). These include two drag-and-drop, single-use "units"--poison gas and an artillery barrage--which are expensive but effective when you used with care. (And since the Germans have access to gas and artillery, too, you have to keep a close eye on your own troop concentrations, because even a second or two of delay can break the back of your advance).
Trenches forces you to keep adapting your strategy on the fly, as you manage your money (which lets you buy more troops), your fortifications (which you can build with your engineer), and the tactical positioning of your units. The game has a smart, adjustable (and at-times brutal) AI to keep you on your toes, and it's difficult to recover once you lose momentum. In addition to the campaign mode, the game also has multiplayer (Bluetooth and Wi-fi) and skirmish modes, with skirmish letting you play single maps with varying objectives and difficulty (including variants like king of the hill and zombie horde).
While Trenches has a lot going for it, it's not perfect: when tested on a 3G, menus were often laggy and sometimes text wouldn't appear (so, for example, you couldn't see your money, score, unit costs, or in-game callouts). The game also slowed down and became unresponsive when many units were onscreen (making the otherwise fun zombie mode unplayable after a few minutes). That said, when Trenches works--which is most of the time--it's one of the best games of its kind.