What do you get when you put together a punk rocker, a vacationing librarian, a badger-shooting knight, and one crazy monkey? Hopefully a Siegebreaker (Out Now, Free), or at least that’s what the hapless kings of The Brookelands need right now. Hordes of zombies and skeletons running amok in an iOS game is nothing new, but Siegebreaker‘s anything-goes plot is undoubtedly one of the kookiest excuses for a Tower Defense title yet. The game’s premise simply defies description so I’ll leave it to the game’s comic book interludes – which ooze good humor and Hanna-Barbera charm – to explain.

As noted in last month’s preview, Siegebreaker’s claim to fame is its movable Tower Defense formula. Rainbow-haired rockstar Keith and his motley crew stick to the mazelike ramparts in each level, bringing the pain to enemies as they file in; the vulnerable king they’re trying to protect, on the other hand, hobbles around at ground level. Both the defenders and the king are repositioned whenever the player holds on one of them and draws out a path over the touchscreen. Siegebreaker uses this concept to its fullest potential, making this one of the most refreshing genre entries in a while! If all your characters are sitting still for even a moment, chances are failure will be swift; since there are only four player characters to go around at maximum, the key is to keep the defenders moving alongside enemies, maintaining contact over a distance. Levels get respectably expansive and feature multiple enemy entrances, so each wave begins with a deliciously frantic reshuffling of the heroes and the king.

This real-time movement stands in for the unit deployment and replacement one would normally expect of the genre, but otherwise the very best of Tower Defense is on tap. Enemy waves grow increasingly thick and interesting, with dastardly units that cast support spells on the horde if they aren’t taken down quickly, change their behavior as they approach the king, or even stun the defenders if the player isn’t careful with positioning. Genre fans may miss real-time unit upgrades, but Siegebreaker does something even more interesting with a performance-based Morale system: the heroes gain progressively higher stat bonuses the longer the king remains unscathed. These become critical to success, so casual players drawn in by the cool line drawing concept should consider themselves warned — Siegebreaker‘s difficulty curve is merciless even among Tower Defense games!

All this will sound splendid to genre veterans, especially given the game’s freemium price model. As they say, however, there’s no such thing as a free lunch! There are two ways to gain the Orbs necessary for upgrading character stats and special attacks between levels: either pony up a little real-world cash via In-App Purchase, or prepare to sink some serious time into Siege mode, where story levels can be replayed infinitely for Orbs at regular survival milestones. On balance, heading into Siege mode is interesting in its own right because the player gets to return to old levels with new characters and upgrades. Also, once the Morale system kicks in, some levels become effective grounds for quickly farming Orbs. It’s just a shame that the Orbs don’t appear during the story campaign, seeing as the king’s sole useful purpose is to abandon his cover to grab them under the player’s direction once the coast is clear. Siegebreaker’s Orb collection routine will certainly gain the same reputation among Tower Defense fans that the dreaded “level grind” has among RPG fans!

But heck, let’s face it — Siegebreaker is one of those freemium games that’s actually worth tossing the dev a buck or two, because if my experience is any indication, you’ll be utterly surprised a game of this caliber is going for free to begin with. Let’s call the price at $1.99 for the 50 Orbs you’d need to make a serious dent in the amount of time you’ll spend getting more in Siege mode over the long haul.

There are just a few complaints that I’d love to see resolved in updates. While the game’s interface is satisfying overall, I felt the movement control was just a tad oversensitive; if the player had to hold on characters just a fraction of a second more before producing a movement command, that would eliminate some mistaken commands the player is sure to execute while panning the battlefield around. Conversely, the radial menu for executing special attacks feels a tad under-sensitive, and a slightly greater touch area for the special attack buttons would be welcome.

Siegebreaker is a bit of an acquired taste in the graphics department with its tiny sprites on the iPod Touch 4, but the characters are all beautifully animated and the portraits hold real charm. The game boasts a standout epic soundtrack as well. Whether you throw a few bucks in the developer’s direction toward the beginning of the game will have a huge impact on how much time you spend with it by virtue of Orb grinding; a completely free playthrough will easily last upwards of ten hours.

iFanzine Verdict: Its mix of path drawing with traditional Tower Defense elements and a fun story leaves Siegebreaker a clear standout in the genre; if you’re a Tower Defense fan, you simply must give this a download! Too bad its grindfest approach to character upgrades cuts into its appeal.