When creating a sequel, developers must be careful about adding enough new content to justify a whole new game while leaving in enough of the original game to avoid losing fans of the series. With Kingdom Rush Frontiers (Google Play, App Store), Uruguay-based Ironhide Game Studio has handled this task deftly, forming a great balance between old and new. The sequel enjoys enough additions and improvements to make it feel fresh and exciting while the core gameplay is the same as the original — and that’s a good thing because the original Kingdom Rush was awesome.

For the uninitiated, Kingdom Rush is a tower defense game. The basic rules of tower defense apply: you build towers along a path that will automatically attack any enemies that come within their range. Your goal is to stop enemies from making it all the way to the end of the path. Tower defense is an extremely saturated genre, especially among mobile and browser-based games, so a tower defense game has to be really special to garner any attention at all. Great art with lots of details, lovingly crafted gameplay, and some mechanical twists all contribute to making Kingdom Rush a standout in its genre. It is among the most successful Flash games of all time and saw great success on iOS as well.

Kingdom Rush Frontiers lets you choose between three difficulty settings and, as far as I can tell, you won’t miss out on anything even if you play through the whole game on the easiest setting. This is great as it truly lets players play the game how they want to play. First-timers will have no problem getting into the action, as the tutorial does a great job teaching the game, introducing new concepts quickly, but one at a time. The easiest difficulty is pretty forgiving on the first couple of levels too. Experienced players will need to go through the tutorial too, but it goes by very quickly and the game really doesn’t do much hand-holding. All four basic towers and a hero are available from the get-go. Like its predecessor, there are three stars to earn on each level and the game is a bit forgiving as you seek three stars. Unlike some hardcore tower defense games, you can let a few enemies through your defenses and still earn the full three stars. As a player who wants to earn three stars on every level, I really appreciate being able to just patch up a hole in my defenses instead of having to restart the match every time a single enemy slips through.

I don’t want to make the game sound too easy. The level difficulty ramps up quickly and each stage presents a different challenge. Layouts where enemies comes at your from multiple locations or you have multiple locations to defend really change up the strategy and keep you on your toes. There are constantly new enemy types to adapt to, including some bosses that lead to truly epic battles. After earning all three stars on a level, you can attempt its Heroic and Iron challenges. Each challenge pits you against more difficult waves of enemies, limits you to one health, and places restrictions on the types of towers and upgrades you can use. Completing a challenge gives you one more star, meaning each level has five stars to earn in total. You can also replay levels at higher difficulties to give you more of a challenge and pursue the handful of difficulty-based achievements. There is a whole lot of game here, fully earning all 75 stars even on the lowest difficulty will provide hours and hours of gameplay.

Towers are divided into four types: archer tower, barracks, mages’ guild, and artillery. Archers shoot fast, barracks produce soldiers that slow enemies down by engaging them in melee combat, mages shoot slow but their attacks are strong and pierce through armor, and artillery is explosive and deals splash damage. The barracks is a particularly clever tower, spawning three ground units that you can move around with the tower’s rally point. Each tower can be upgraded four major times, with two different specialized towers available as the fourth upgrade. These specialized towers can be upgraded even further in specific ways, such as the Crossbow Fort’s Falconer ability providing nearby towers with extra range or the Assassins’ Pick Pocket ability that gives them a chance to steal extra gold when they kill an enemy. The towers are all clever and fun to use.

On top of the towers, you have two special abilities you can use, a spell that calls destructive meteors down from the sky and a call for reinforcements that places two troops on the ground. They have no cost other than their cooldown, so it is encouraged for you to use these abilities frequently.

Your towers and abilities can receive semi-permanent upgrades outside of combat. These upgrades are purchased at the cost of the stars you earn from completing levels. The upgrades are minor compared to upgrading your towers during a stage, but they add up over the course of a stage and spread across many towers. The best part about the upgrade system is that you can reset your upgrades at any time for free. This lets you constantly change the way you distribute your stars and adjust your play style accordingly — something that is extremely useful for adapting to the various restrictions of the Heroic and Iron challenges.

The last piece in your offensive arsenal is your hero. Heroes are particularly powerful units that you can move around the entire map. They will attack enemies and have special abilities they will perform on their own. While most of the changes from first game to this one are minor, the hero system has been completely overhauled. In the original, unlocking heroes cost 15 of your precious stars. Frontiers, on the other hand, lets you use heroes for free. This is a welcome change as heroes are a lot of fun to use but 15 stars was a huge sacrifice when most tower upgrades cost three stars or less. Heroes can level up by dishing out damage and using their abilities. In the first game, your hero would start at level 1 on each map. In Frontiers, each hero’s experience and level are persistent across all levels. When a hero levels up, they receive several hero points that you can use to upgrade them. Each hero has five different upgrades that have three stages each. Hero upgrades improve their stats or give them new abilities. Like the tower upgrade system, a hero’s upgrades can be reset at any time so you can reallocate their hero points. The tower upgrade system is one of the coolest parts of Kingdom Rush and the hero leveling and upgrade system is an awesome addition that makes heroes a lot more fun to use.

Each hero plays differently. For example, some deal lots of damage to single targets, some can target several enemies at once, some have ranged attacks, and one can heal your troops and grant boosts to your towers. Like the first game, Frontiers allows you to unlock three heroes for free and extra heroes via in-app purchase. The heroes this time around are a lot cooler than last time and include a stone golem, a Protoss-like alien, and a fire-breathing dragon. Of course, the coolest heroes will cost you several dollars apiece. Even so, the new hero system makes all the heroes seem much more powerful. They are all pretty great, the hero you start the game with is a desert warrior who wields a scimitar and summons sand monsters.

The same excellent art style makes a return, courtesy of lead artist, Gonzalo Sande. As always, the characters and animations are charming. I’m particularly fond of all the comic book onomatopoeia that pops up in combat. KBOOM!, SHUNT!, and POW! colorfully litter the screen when the action heats up. Everything looks a little better than before, particularly the backgrounds which enjoy an even greater level of detail. Each stage has a unique background filled with cool things to find and interact with. Tap around the environment and it will reward your exploration with silly animations and even achievements. You’ll find exploding livestock, dancing frogs, mythical creatures, and all kinds of other goodies. The stages are divided into three terrains: sandy deserts, pirate-filled jungles, and underworld caverns. I spotted several Star Wars references just in the first few desert stages, including Tusken Raiders that snipe enemies from across the stage and Banthas that… well, I’ll let you discover that one on your own. Each stage also has unique features that can help or hinder your cause. Some buildings will simply contribute to your cause by automatically attacking enemies while others will take your money to provide you with themed mercenary troops (e.g., genies and pirates). Other stages feature ships that will fire on you or sand worms that will devour ground units.

The music is varied and exciting to battle to. Best of all in the sound department, heroes and towers each have several voice acted lines that ooze personality and really make them come alive.

The gameplay is an excellent blend of strategy and action. It is paced extremely well and there’s almost always something to do. Even beyond all the normal tower management (buying, upgrading, selling), you have abilities to cast, a hero to move around the stage, and ground troops to shuffle around their tower. The game definitely generates some hectic moments, but they are always the kind of exciting moments that make you laugh instead of feeling unfair or frustrating. Ironhide makes this game really easy to love and most any gamer should be able to get into it easily, unless Tower Defense is just a genre they hate to play.

There are some very minor things to complain about. The hitbox for towers is too small and a little too high. I missed towers often when I tapped where I felt like tapping. I eventually got in the habit of tapping the tops of towers, but it felt weird that I couldn’t tap a tower’s base to select it. Also, some iOS-specific issues that are often complained about are present, such as the lack of a Universal version, no iCloud support, and some cool heroes that can only be unlocked via somewhat pricey in-app purchases. None of those things stopped the first game though and I would be shocked if they got in the way of this one’s success.

Kingdom Rush Frontiers makes some minor changes to Kingdom Rush without taking anything away. Every change is for the better and the subtlety of most of the changes really shows the love that Ironhide Game Studio has for its craft. If you liked the original, you would like the sequel. If you didn’t like the original, you probably won’t like Frontiers. If you have no experience with Kingdom Rush, you could always try the original Flash version online for free.

Honestly though, if you like games, you are probably safe to dive right in and enjoy a truly awesome entry in the tower defense genre.

Note:

App Store Link: https://itunes.apple.com/us/app/kingdom-rush-frontiers/id598581396?mt=8

Google Play Link: https://play.google.com/store/apps/details?id=com.ironhidegames.android.kingdomrushfrontiers