Orcs Must Die! has done something I'd thought impossible: it's a tower defense game that actually gets deeper and more rewarding the longer you play it. The joy comes not just from the sadistic delight of watching a wall-trap viciously fillet a crowd of almost lovable cartoon orcs with a series of spinning-blades, but also from the Portal-like cycle of running into a tricky problem, taking a break to ponder it, and then racing back to try a new solution.
With friends' scores taunting me on my personalized leader board (my Sunday night was ruined by Dan Stapleton knocking me off the top of every single level), I'm constantly trying to design even better murdermazes on early levels. The first time through I only had a few tools, but in playing through the lengthy series of levels I've now unlocked at least a dozen different traps and special powers. Every time I got a new toy, my mind immediately ran wild with the possibilities of elegant abattoirs that I could create on some of the nettlesome early maps.
Spiked pressure plates on the floor are all well and good, but a spring trap that launches flailing orcs helplessly into pools of lava is more stylish. I also delighted in the cruel irony of a push trap that shoves surviving orcs back into the same gauntlet of traps they just escaped.
The traps are the most fun way to dispatch orcs and their allies (like fast-moving rat men and huge, hard-hitting ogres), but using my War Mage to personally slay, shoot, and fry them in third-person view can often be the difference between victory and defeat.
He's basically Gandalf's intern – a wizardly fratboy of dubious competence and limitless arrogance. I don't like his attitude, but when he's equipped with the awesomely powerful Flame Gauntlets, it's hard to deny he's an essential part of any defense. Still, you get more points for killing orcs with an elaborate combination of traps and minions (archers, for instance), so earning a high score is a gruesome balancing act of slaughtering the hordes by hand and feeding them into your machinery of death.
And even with its whimsical, World of Warcraft-derived art style, it certainly is gruesome. There are moments of eye-popping carnage as orcs are chopped into pieces, or sent catapulting through crowds of their fellows before plummeting into waiting acid pools.
Orcs Must Die!'s levels defy easy solutions, and that's what sets it apart from other tower defense games. Solutions themselves change in hugely interesting ways as you bring more advanced items and powers back from the later levels, giving a challenge that not only doesn't pale with experience, but actually grows richer. Not since Lemmings has a game so seamlessly mixed engaging mechanics, humor, cuteness, and gleeful cruelty.
Possibly the best of its genre, Orcs Must Die! is clever enough to keep evolving before it ever gets boring.