CastleStorm is the latest in a series of games hitting the Xbox One marketplace with the 'definitive edition' tag — promising an improved version of the original title (presented in glorious HD), as well as all the prior DLC and some extra content. In the case of this release, the extra features include two expansions, 20 new single-player battles, 4 new extreme survival battles, 10 new magic spells and a host of graphical improvements.

You begin the game as Sir Gareth, a self-assured knight who commands the activities of a small army trying to fend off attacks from the Viking forces who are trying to steal a magic gem which has kept the peace for many years. There's just enough story to keep you interested in single player without feeling the need to skip forward to progress. The voice acting is limited to a couple of words or a grunt here or there to accentuate tone. It's a comfortable game in the way that it looks and sounds exactly as you'd expect of it — the dialogue will raise the occasional smile even if it's fairly predictable. This is not a criticism by any means, as CastleStorm occupies the same gaming space as titles like Boom Blox and Angry Birds. It's all about perfecting your strategy to earn the coveted five star rank on every level. The cartoony art-style and lighthearted music perfectly capture the spirit of the game - although it looks simple, there's real complexity here.

The action is all presented in 2D, with the player usually controlling a castle on the left side of the screen and defending against attackers closing in from the right. At first you'll fire your castle's ballista weapon at the enemy to keep them at bay. Later, you'll spawn troops, such as knights and archers, onto the battlefield to fend off ever increasing hordes of Viking attackers. It's even possible to take to the battlefield yourself by beaming Sir Gareth down into the action for 30 seconds at a time to do some real damage to the enemy, turning this into a brawler for short bursts. Just when you've mastered these mechanics, the rules change again and you'll be tasked with bashing down the enemy's castle gate and stealing their flag. Only spawned troops can do this though, so it becomes even more important to keep them alive so they can make their way over to the other side of the map and return with their prize. This is around the time that most people will notice that friendly fire exists - there's nothing worse than watching your projectile score a perfect headshot on your flag carrier. Since troops are limited in number and can only be spawned when you have stored enough food to maintain them, they aren't a resource that can just be thrown into the battlefield and shot in the head for fun.

While defending your gate, spawning and commanding ground forces, popping down to the battlefield to have a shot at hitting things, casting some of the many available spells, and shooting your own (and sometimes the enemy's) troops with the ballista, there's also going to be the problem of the enemy trying to destroy your castle by hurling rocks, hammers, sheep and numerous other types of debris at the more vulnerable parts of the structure. The best way to deal with this is retaliation, and thus the Angry Birds style destruction physics take over. Essentially, each castle is made up of blocks, and each block can be decorative for a bonus room/troop room. Throw enough shrapnel or hogs at a block and it'll crumble and fall down, occasionally taking further parts of the castle down with it. Once a room is destroyed, it no longer works, so if the enemy keeps annihilating your troops with goblins, it would be wise to throw all the bombs you can find at the goblin room in their castle until it's nothing but dust and bones. This works both ways though, so it's vital to keep an eye on your castle to ensure it doesn't get destroyed (while also spawning troops and defending and all the other junk you have to do). It's not always easy, and employing the wrong strategy can let it get out of control fairly quickly.

The built-in castle editor allows the player to customise their fortress to their own specifications. As there's a limit to the number and types of rooms in each building, this becomes a more complex exercise than it first seems. Pure Xbox's Fort Fantastico took 30 minutes to build and, despite and impressive amount of spikes on the walls, still isn't perfect. The editor is really simple and painless to use and includes a test mode so that you can see what works and what doesn't. It's also fun to sit and destroy castles in test mode because, well, destroying things is fun. It's worthwhile creating a few customised castles, as this allows a personalised balance of troops and equipment to suit individual play styles.

It's important to mention just how long this game is. The inclusion of two expansion packs and some extra levels means that there are easily over 15 hours of play here, and many more for those who want to achieve a five star rank in every level and get all the upgrades. Everything can be upgraded, from bonus rooms to troops and spells. If you have enough gold there's an upgrade available and it quickly gets expensive. This is what will initially drive players into the side quests and back to the early missions, but completionists will be heading there anyway.

The main criticism that can be leveled at CastleStorm is that it can get a little repetitive once you have mastered the balancing act of managing the many different aspects of siege warfare. There are other modes and multiplayer, but these don't offer much of a change from the norm. Survival let's you play solely as your hero on the battlefield, fighting off wave after wave of attacker and defending your flag, but with only three attacks available, this becomes boring very quickly. The aiming assist line on the ballista can occasionally be hard to see as well, but this becomes irrelevant once you're on your third consecutive hour of playing having sat down to do 'just one level'.

Conclusion

If multiplayer Versus is as good as the single player, then this game deserves a slightly higher recommendation. Unfortunately, at the time of writing this review, the only multiplayer modes which were functional were the repetitive and, frankly boring, survival modes. Don't be put off by this though, as there's an awful lot to keep you busy in single player, and it would be a shame to miss out on this quirky gem. The graphics and art style compliment the overall feel of the game, which is lighthearted but with plenty of depth. The script is charming and story is delivered in bite-sized chunks, perfect for this kind of pick-up-and-play title. The mechanics are simple yet engaging, and the merging of tower defence, brawler and castle destruction is the ideal balance of easy-to-play yet difficult-to-master. Simply put, CastleStorm has a lot going for it.