Take back the tower.

From the creator of Age of Empires II comes a game that has been a source of serious addiction for many PC gamers since December of last year. A member of the relatively new Tower Defense genre of games, Defense Grid: The Awakening starts simple and banks on its infectious fortification mechanics while slowly building in more variables. It’s immediately intuitive—especially with the excellent spoken-dialogue tutorial throughout the first few missions—and it’s very difficult to put down. For just 10 bucks, it’d be hard to find any reason not to recommend this to any RTS fan.

The premise is simple enough (quoting near-verbatim from the game): After thousands of years of peace, aliens return to a planet to terrorize it. The planet’s survival depends on activating the ancient Defense Grid… if it still functions at all. As the aliens appear in wave after numbered wave, your job is to protect your tower “cores”, which are like little pellets that aliens are after. They make a beeline for the core repository, pick up as many as they can carry, and then head for the exit (which often is the same as the entrance). As you might expect, once they make off with all of them, you lose.

Fight Back

Fortunately, you have some defenses at your disposal. Throughout each map are special little squares. On these squares, you can construct a variety of different defensive tower structures which will automatically fire on the aliens as they move within their radius of attack. Of course, the towers take a few short seconds to construct, and they also cost money—so the number you can build is limited by those two factors. How do you get more money? Kill aliens, of course!

Some of the different tower types in your arsenal include:

• Gun Towers – These fire a machine gun at a single passerby until it’s dead or it moves out of range.

• Inferno Towers – The wide blaze these create can blanket a group of aliens effectively, but it’s weak on single threats.

• Laser Towers – These fire a laser which continues to damage the alien even after it escapes.

• Temporal Towers – These fire short bursts which slow any alien to half speed if it is hit.

• Meteor Tower – These towers fire from an extremely long range, but they can’t hit anything close by, and their rate of fire is slow.

• Cannon Tower – Along with the gun towers, these are the only ones which can hit flying enemies. They’re also effective for medium-range attack on ground threats.

It’s also possible to upgrade towers to improve their range, rate of fire, and attack power (think Command & Conquer). There are three levels of power for each tower, but getting them to their best costs a pretty penny.

As for the aliens, they’ve got an assortment of different varieties on their hands as well. You’ll find aliens that are slow, aliens that are fast, those which have shields or can fly, and still others who can spawn more aliens at regular intervals. There are even “boss” aliens which are considerably harder to take down, but which move at a much slower pace. You can view the progression of oncoming aliens (who have yet to reach the playing field) through a quick glance at a meter at the top of the screen.

As you progress through later levels, you’ll find increasingly-complicated linear pathways for the aliens to take toward and away from the cores, making tower placement ever trickier. Even further, the levels open up beyond linearity to allow multiple paths through the playing field for the aliens. At this point, you have to strongly consider how tower placement regulates the aliens’ routing; you can prevent them from walking through an area with adjacent tower placement blocking the path, so the idea is to force them to take the longest possible path with the most arduous firepower decorating their journey.

It’s progressively more important not to let the aliens reach your cores as the level designs complicate, though; once they carry it off, it moves more slowly back toward the base, making interception by other aliens much easier—especially as the winding paths intersect in the later levels. This can quickly degenerate into a bad situation if you don’t stop the bleeding early on, as the game is vicious enough to send boss aliens followed by large groups of fast-moving enemies to help facilitate this sort of stress. And that’s not to mention the other submechanics that surface later on in the experience: for instance, your resources recover more quickly if you spend less… but stolen cores reduce those rewards.

Addictive and Accessible

Of course, failure becomes a fact of life when you reach the later missions, most of which demand at least several tries before you perfect your timing and placement strategies. Wisely, however, the designers have implemented a painless retry system that rewinds to the most recent autosave checkpoint with a quick press of the Back button on the controller. There’s no penalty or anything like that for taking advantage of this feature, and you can actually go back as many checkpoints as you wish (typically checkpoints happen every 3 – 4 waves). That means that even failure doesn’t hurt so bad, and it only serves to make the game that much more appealing and accessible—especially to gaming geezers like myself (of 27 years… yeah, I know, tell me about it), who have grown impatient and intolerant over the years.

If you’re worried about this ease-of-use feature making the game too simple, don’t—there are plenty of levels to work through (twenty in the main campaign and four additional bonus maps), and they’re more than sufficiently tough. You’re awarded medals based on your performance, and your best efforts are sent to the leaderboards for the usual depressing comparisons with friends and strangers. And when you’re done with that, there are countless challenge modes to chew on as well, which add modifiers such as income restrictions, “poisonous” cores with limited income (where a loose core is used as a weapon), tower restrictions, and much more.

Full Disclosure: Reviewer completed just over half of the main campaign and attempted various other play modes included. He’s also a self-proclaimed perfectionist, so he managed to only lose a few cores over the course of his foray into the campaign. He then logged onto the leaderboards and became hopelessly discouraged, yet strangely invigorated. He will certainly be neglecting his wife and dog over the next several days as he continues his efforts.