Castle Defense games for iOS

This week's collection of iOS apps is all about castle defense games. The first has a World War I feel as you battle your enemies across a series of dug-in trenches. The second lets you play as a character from the popular Evil Dead franchise as you fight off skeletons and other ghoulish enemies. The third is a new game in which you'll choose from three races to fight your enemies in a humorous quest to create the ultimate barbecue sauce.

With the introduction of the touch screen on smartphones, game developers had to come up with new control schemes that would work intuitively on the iPhone. And as iOS games evolved over time, new genres of games started to crop up that were perfect for touch screens and on-screen buttons.

One of those game genres is the castle defense strategy game. Even though you could play desktop and browser-based versions of these games, the touch screen on the iPhone worked so well that they were incredibly easy to pick up and play.

This week's collection of iOS apps is all about castle defense games. The first has a World War I feel as you battle your enemies across a series of dug-in trenches. The second lets you play as a character from the popular Evil Dead franchise as you fight off skeletons and other ghoulish enemies. The third is a new game in which you'll choose from three races to fight your enemies in a humorous battle to create the ultimate barbecue sauce.

Trenches (99 cents) 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 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.

Army of Darkness Defense (Free) is a castle defense game based on (and named after) the third movie in the cult-classic comic-horror series "Evil Dead." You play the chainsaw-armed hero Ash Williams, and audio samples of his highly quotable dialogue play a starring role in the app.

Unlike so many movie tie-in games, Army of Darkness Defense manages to be quite good: it's a mix of resource management and arcade action, in which you reenact the frantic defense of the movie's finale. Waves of enemies--skeletal and/or demonic "Deadites"--advance from right to left inside the scrolling castle interior. You move left and right (by tapping either side of the screen) and fight them yourself, with a shotgun autoattack and upgradeable special abilities. You also fight them with allies you call to your side, from peasants and swordsmen to heroes like Lord Arthur, Duke Henry the Red, and the healing Wiseman.

The gameplay revolves around choosing which units to build and when, earning gold by surviving each level's onslaught, and then using that gold to upgrade your abilities, castle, and units in between levels--but you don't have enough gold to upgrade very many of your special abilities and units, so you have to prioritize. You can also collect some gold (and iron bars, to speed up unit production) from fallen enemies while you're fighting--and that makes for some fun, fast decision-making, as you weigh whether to risk the melee for a quick boost to your resources.

Fans of both castle defense games and the movies (especially Ash, aka the goofy, over-the-top Bruce Campbell) will find a lot to like here. The game's only weaknesses are a lack of variety--you defend the same castle for 50 levels, followed by an infinite mode--and the potential to paint yourself into a corner strategically, requiring you to buy more coins as an in-app purchase. Overall, though, Army of Darkness Defense does a good job of balancing its core gameplay and its in-app economy, and many players will likely buy in-app currency just for access to more and more entertaining powers (like Ash's Deadite-reaving 1973 Oldsmobile Delta 88, the "Deathcoaster").

Swords and Soldiers (99 cents for a limited time) is a castle defense strategy game that's fun to play and has a sense of humor. Your job is to command an army of Vikings with the goal of creating the ultimate barbecue sauce. Later in the game you'll also be able to play as Aztecs or Chinese Warriors, each with individual skills and units.

The graphics in Swords and Soldiers are crisp on the iPhone 4 Retina display, featuring cartoon-like characters and colorful 2D backgrounds. The interface involves swiping horizontally to see more of the map, and on-screen buttons for creating new units (once you've purchased them) and other skill buttons like healing and calling in aerial attacks. All the interface elements are done very well and the game slowly introduces you to each making easy to get up and running quickly.

You get a few different game types including Campaign mode, which lets you slowly go through each level of the game and unlock the extra races. A skirmish mode lets you jump into the action right away, letting you choose your map size, your race, and gives you all the upgrades as long as you can afford them. There is also a challenge mode you'll unlock once you've finished the Campaign, which lets you fight through survival, berserker, and boulder game types. With the long campaign mode and other game types, Swords and Soldiers offers plenty of content to give it great replay value.

Overall, if you like castle defense strategy games, Swords and Soldiers offers plenty of content, challenging gameplay, fun units to unlock, crisp graphics, and a sense of humor that will make you chuckle as you defeat your foes.

Got a better castle defense game not shown here? Please let us all know about it in the comments!

About Jason Parker

Jason Parker has been at CNET for more than 13 years. He is the Senior Editor in charge iOS software and has become an expert reviewer of the software that runs on each new Apple device. He now spends most of his time covering Apple iOS releases and third-party apps.