Editors' note: This review has been updated with information about syncing between devices.
Kingdom Rush Origins (iPhone|iPad|Android) is the third installment in a well-established tower-defense franchise that includes improvements on the same great gameplay from earlier versions and new features to keep it interesting.
The Kingdom Rush series uses a fixed path (instead of an open field) where you place towers on fixed emplacements, and gradually changing levels bring new challenges as you play. It also has special abilities you can use to nuke areas of the map in an emergency, and a hero system that lets you bring in one specialized player to balance your defense.
When I saw that there was another installment to the series, I wondered what developers Ironhide Game Studio could do to keep the game fresh. But even when I realized the core mechanics were the same, all the new tweaks still make it worth the price, with tons of levels and new content to explore.
As the third game in a very polished series, Kingdom Rush Origins lets you jump right into the action and -- even if you haven't played the earlier games -- tells you how to build your defense against the enemy onslaught.
You start with enough gold to construct a few towers, but it's important to check the map to see where your enemies will be coming from. If you end up building all your towers by a single entrance (there can be multiple entrances), the second the enemies use another entrance you'll be scrambling to take them out before they make it to the end.
As you play through your first couple games, you'll learn about heroes you can use and upgrade, the different types of monsters, and how you'll need a mix of towers in order to be successful.
As far as content, there are tons of levels to play throughout Kingdom Rush Origins and three skill levels to give it plenty of replayability.
It's all about the upgrades
Each level gives you a number of lives. If the number of enemies that pass through the exit is more than your remaining lives, your round is over. The only way to stop that from happening is to upgrade.
You get four defense towers to choose from that give you different types of attack power including elven infantry, elf archers, mystic mages, and stone druids. The infantry is the backbone of your defense, fighting on the front lines as it defends a path. But they also slow enemies down so you can really deal damage with your other towers. In other words, using a mix of towers is the best bet.
Each of your towers can be upgraded to give them more attack power and more attacks. For example, the elven archer tower starts with just one archer, but you can upgrade it up to three archers for triple the attacks. But even beyond that, you can upgrade the type of arrows the archers use and add sleep poison to the arrows or burst-shot abilities. In between games you can upgrade the overall power of each type of tower as well, so it's important to keep adding points earned to each tower type so they're stronger overall.
Choose and upgrade your heroes
Along with your towers and special nuke abilities, you can also have a strong hero on the battlefield you can control. You can use heroes to attack particularly strong enemies, or to fortify areas of the map that are vulnerable to attacks by moving them into position.
There are nine different heroes to choose from, each with their own set of abilities. For example, a mage type hero would be a ranged attacker, where a melee hero will battle on the front lines, but the abilities for each can be upgraded between games using points from your winnings.
Each hero has five different abilities that you can upgrade. So, in the case of Arivan the mage, you can choose to upgrade his fire, ice, snow or earth attacks, or add points to his elite ability that sends a tornado down the path that shoots lightening as it hits several enemies at once. Which heroes you use and how you upgrade them is up to you, but you'll find that having a good mix to choose from will help you get through the tougher levels.