Orcs Must Die! is an original take on the Tower Defense genre of strategy games. We've seen a few twists -- such as Army of Darkness Defense -- though most stick to a basic set of mechanics. Though Orcs Must Die! sticks to a couple of core concepts, it adds the fun of hack n' slash gameplay, creating an interesting variant to a familiar model.

Art style is everything for Orcs Must Die! It is pleasing and fun to watch, but also allows the developers to get away with all sorts of mayhem. It's not enough to launch a couple of orcs into an acid pit or smash them with all manner of large objects, but Orcs Must Die! lets you dismember, explode and otherwise impale anything unlucky enough to enter your trap-filled amusement park. With a darker, more realistic coat of paint, I'm not sure the game would be nearly as enjoyable as it is. Not that I have a weak constitution, but it's just easier to watch body parts fly when they're attached to big cartoons rather than realistic models.

It should be noted you can turn off the blood if you want.

An equally enjoyable soundtrack backs up the fun art style. It sticks to the medieval fantasy theme, but remains upbeat. You also get a fun assortment of enemy chants and your hero's multiple quips aren't that annoying.

Orcs Must Die! is one of those rare games where the title tells you everything you need to know about gameplay. You play as a rookie War-Mage tasked with keeping orcs from escaping through Rifts (portals) after your master has an unfortunate mishap with kobold blood and the pavement.

The core idea behind Orcs Must Die! isn't much different than other Tower Defense games. You're handed an assortment of damage-dealing traps to set up along a set path leading to the Rift. Where Orcs Must Die! differs is how you place traps; between waves, you run through each maze, figuring out the best places to drop traps. Sometimes, it is as easy as finding a choke point, though most of the time, you're faced with multiple hallways to defend, forcing you to really think about how you're going to shepherd the incoming hordes through the level.

Another difference is you can take a more hands-on approach to Rift defense. Rather than setting traps and hoping for the best, you can arm yourself with a number of spells and weapons to help hold back the crush of enemies. You start with a crossbow and blade staff, both of which are great equalizers, but eventually gain access to items like the whirlwind belt, which not only lets you hold enemies in place, but also sends a gust of wind into enemies, knocking them into traps. Eventually, you add Weavers to your arsenal - sorceresses who can add extra protection and spells.

Since you're only allowed to bring a set number of traps and abilities into a level, situations become more puzzle-like. Orcs Must Die! isn't something you can easily master; there are simply too many solutions to each predicament. Yet, it is something you can sit down with and play for hours, even if you find yourself constantly overrun by certain enemy configurations.

The one downside is longevity; once you've cracked a level and earned a five-Skull rating, there isn't much incentive to return, unless you're aiming for the top spot on the leaderboard. You'll also unlock Nightmare difficulty, which is a cool bonus for hardcore Tower Defense nuts only.

Orcs Must Die! starts out easy, challenging you to protect a couple of narrow hallways with easy-to-identify choke points. The minute you see multiple access points or - gasp! - overhead walkways, it seems intimidating. What really stands out is accessibility. Even the most daunting of levels isn't as scary as they originally seem. You're never handed a challenge you can't overcome. You may allow a couple of Orcs to slip past you and into the Rift, costing you points or Skulls, but you're never overrun with impossible odds.

Later levels do place you in challenging situations. You're never sure of what is coming next or, more importantly, where they're coming from. Though not a massive problem, it is completely possible to get into a situation where you fall on the last wave. Thankfully, waves and patterns usually remain the same between tries, so even if you do die, you can always come back with a better idea of what you're facing.

Traps are everything in Orcs Must Die! and you're handed several ways to defend the Rift. Spikes, arrow-launching walls, spring-loaded platforms, burning coals - take your pick. The sheer number of orc-crushing tools may overwhelm some players. Yet, you're given so much freedom, it is possible to lean on a couple of core strategies, as you learn how to incorporate new items into your repertoire. Figuring out new, more effective ways to keep the orcs from the Rift is great. Most of the fun comes from building up combos of devices. For example, arrow-launching walls are great fun, but are even better when paired with black goo, which slows orcs down. Or, if you're looking for maximum damage, you can pair the wall launchers with upgraded floor spikes, which add a "grip" effect when sprung.

Placing traps is very easy. After choosing the right trap from the spell book, a transparent model appears. Everything is mapped to a grid and snaps right into place, removing the hassle of trying to place a trap in the right spot. The biggest challenge is figuring out how to get the most out of your limited funds. It is, however, possible to misread your situation and place traps in bad locations or bring the wrong tools for the job. In both cases, you aren't completely screwed and can usually MacGuyver together some defense plan. You can also "sell" misplaced traps, so nothing is permanent.

Orcs Must Die! is, without question, one of the most entertaining games I've played this year. Both the levels and strategies at your disposal are enough to scare away some players, but all of the fear quickly goes away the first time you see a spike impale an orc. It's sick, but a lot of fun.