If you haven't played the original Orcs Must Die!, suffice to say it was generally well received for its blend of tower defense, third-person shooting, and flippant humor. Just like the dungeon crawler Torchlight, the biggest complaint most people had about Orcs Must Die! was its lack of multiplayer options, and the sequel aims to remedy that as well as introducing new mechanics.
In the original, the protagonist warmage is tasked with defending the fortresses of the dead world against a horde of orcs, lest they find their way through the magical rifts into the real world. This time around, things are reversed, at least to begin with, as our irreverent warmage finds himself working in the dwarven mines following the events of Orcs Must Die!. New rifts are now opening in the mines, and the warmage must keep the orcs from escaping the mine and getting to freedom in the real world. He's also got some help in this endeavor from the first game's antagonist-turned-partner, the sorceress. Together they team up, and trade witty and not-so-witty banter as they defend the real world from the orcish hordes. The setup is basically the same as before, however several new features expand on earlier gameplay, both to make harder levels more accessible, and to provide new ways to play the game.
The most noticeable addition is the sorceress herself. Although billed as a new character class, her differences from the warmage end up being rather minor all told. She has less health, more mana, and different starting gear, which lends her to a slightly more strategic playstyle. Her wand's secondary attack is able to charm an enemy and make it fight other enemies. When used on some of the tougher enemies such as an ogre or an earth elemental, it's pretty effective crowd control.
In Orcs Must Die!, players were awarded skulls based upon their performance for each level. These skulls could be used to purchase new weapons and traps for your spellbook. If you wanted more skulls, it was an incentive to go back and replay older levels until you got a perfect 5-skull rating. This time around, that's still the case, but Orcs Must Die! 2 adds a new "endless" mode (it actually does end, eventually, when the orcs overwhelm you) where players can earn extra skulls regardless, but more skulls are still awarded for better performance. So if you get stuck somewhere and think a new trap or weapon would have made the difference, a few games of endless mode will let you get back into the game.
There's another new way to get help if you find yourself stuck in Orcs Must Die! 2, and that's to team up with a friend. The new multiplayer feature lets you team up with a friend, which can help covering multiple orc routes on the same map. The multiplayer has been done via Steamworks integration, however, so your fellow orcslayers have to already be on your Steam friends list. For myself, I already planned on only playing the game with Steam friends, but I can see where someone would take issue with this. It nearly rules out the idea of casual multiplayer where you just pop in and play a few games with a stranger, unless you want to friend a stranger to begin with.
Orcs Must Die! 2 continues the same system of dual currencies as well. There's coin earned during the course of each level that's used to buy traps, and the skull currency that's used to buy upgrades for your spellbook. The spellbook in Orcs Must Die! 2, however, has been greatly expanded, and now in addition to traps and weapons there's several buffing items and new costumes. Most traps also let you spend more skulls to increase their effects or to add new effects to their use. For example, you can buy a ring of chain lightning for the sorceress, and then spend more skulls to make the lightning jump to more targets, or to add a stun effect to it as well. This allows players to tailor their spellbooks to their own personal playstyle.
There's a few new mechanics present to help out our warmage and sorceress. The mine levels of Orcs Must Die! 2 add pre-placed mine cart tracks which will periodically send a cart barrelling into a mob of orcs. There's also a track switcher to choose which set of tracks the carts run on, adding another option for orcslaying. The early levels also contain several pre-placed traps, so players can see the traps in action and learn how to use them, and decide if it's worth buying the traps for the spellbook.
Despite all of the new stuff, there's plenty that's old as well. Many of the art assets are reused without modification, and the high fantasy meets hip hop soundtrack of the game is the same music as the first. Because of this, it feels more like an expansion pack instead of a true sequel. The release date of less than a year after the first game doesn't really help it feel less like of an expansion pack either. A bonus only available to owners of the original Orcs Must Die!, is the inclusion of ten levels from the original game, for use in single-player and co-op modes.
I would recommend this game to anyone who enjoyed the first but wish they could play it with a friend, or to someone who really enjoyed Dungeon Defenders or Sanctumo and wanted a break from the endless grind-fest of Dungeon Defenders. I'd also really like to see this game get the Humble Bundle treatment in the future, but with its reliance on Steamworks, that may be asking too much. At the very least, more ports aside from Windows and Xbox Live Arcade would be nice. As I mentioned before, the game feels more like an expansion pack to the original than a true sequel, however at it's low price point (15USD, 12GBP) it's priced less than DLC for a big studio game. At that price, they can call it whatever they want. It's cheap fun, and well worth a purchase.