If our children learned their history from video games they would probably believe that the only two things we did in medieval times were slay dragons and siege castles. Scratch the dragons and that's not too far off. Knights Onrush embraces that classic medieval past-time of sieging neighbors castles and places you at the helm of defender. Can you protect your palatial estate from hordes of adorable little knights?

The gameplay behind Knights Onrush, like most castle defense games, is fairly simple. Knights will enter from one side of the screen and quickly make their way to the other. On that opposite side of the screen? Your castle. You'll need to eliminate these knights by any means necessary in order to protect your medieval homestead.

The most basic and most commonly employed maneuver in defending your castle is the finger flick. Touching an enemy lifts him off the ground, and a flick of the finger will toss him in whatever direction you wish. Eventually they'll come crashing back to the ground with a somewhat bloody thud. Each of these kills earns you gold which you'll spend when the day is done to purchase new defenses for you castle.

You'll get to pick from a fairly decent assortment of weapons and defenses. Stronger doors, big boulders, fire.. The list goes on and on, even going so far as to include a freeze ray (odd for ye olden days) and a giant column that lets you smash dozens of bad guys at once. The increased defenses cost more than gold though; many of them require sacrifices be made. This means that one of your first purchases will be a Dragon Altar or a Hell Gate. Rather than throwing a bad guy, you can place one of them in these devices to earn sacrifice points that can later be spent on the better defenses.

Presentation in Knights Onrush is endearingly adorable, yet occasionally grotesque. The game seems to take its visual cues from the same place the folks behind last year's Xbox Live smash hit Castle Crashers did, presenting us cute little knights with disproportionately large heads to try and defeat. The flip side of the coin? Once defeated they're limbs fall off and blood spurts out. It's definitely a strange mix of sweet and sour, but it's somehow fitting with the gameplay.

The main campaign offers up 12 castles to defend, each for a set number of days ranging anywhere from 7 to 30. Each “day” can last anywhere from 2-10 minutes. This means that, while some levels can be completed in a 10 minute window, other could take you upwards of an hour. In terms of value, that's a tremendous amount of gameplay for your $4.99. In terms of iPhone friendliness though? It may be difficult to complete a game in one sitting, which is a bit of a turn off considering the medium. On the other hand the game will autosave if you need to bail out 40 minutes in to get on with more pressing matters in life.

Each level offers up a good deal of variety in terms of spreading out the introduction of enemies and what combinations of enemies you'll see. It's something that keeps you on your toes and makes sure you can think and react quickly to an ever-changing situation. As far as castle defense games on the iPhone go, this is definitely one of the better ones so far.

Still, that's not to say the game isn't without flaws. The placement of defensive structures on the castle is tightly packed, and more often than you'd like you'll find yourself firing off your ballista when you needed to use your fireball. As well, while strategy definitely plays in while tackling different enemies, it's still far too easy to find your favorite defensive structures and just stick with them, rather than being forced to try new defenses due to the abilities of different enemies. Some defenses also require aiming, which seems completely unnecessary as all enemies come in from the same path. What's worse is that the aiming is very sensitive, which frequently leads to a rogue fireball or freezeray shooting miles from anywhere an enemy can even be seen.

The developers at MoreGames have promised some additional content for Knights Onrush down the road. More levels, more enemies, more defensive structures, and boss battles will all be added to the game in future updates. Publisher Chillingo has a good reputation for making sure their games are supported with fresh content well past their original release, and it looks like Knights Onrush will be no exception. Combine that with the extra modes packaged with the original release (Endless, which as the name suggests goes on forever and Madness, which is a brutally difficult version of Endless) and you've got a title with a good deal of longevity.

Chillingo have developed a reputation as one of the iPhone's leading game publishers, and Knights Onrush does nothing to tarnish that reputation. There's a great deal of game to be had for the $4.99 that's asked, and if you're into castle defense games you'll be hard pressed to find one better on the iPhone. It's a shame that there were enough minor problems with the defensive structures to really hamper the experience from time to time, because without those this could easily have described as a landmark title in the genre.