What do you want from a Kingdom Rush sequel? If you answered “more Kingdom Rush”, then you're in luck, because that's exactly what Kingdom Rush: Frontiers delivers. It's just as polished, just as well-balanced, and just as addictive as its predecessor.

But if you gave a different answer, you're going to be disappointed. Where the original Kingdom Rush carved out the genre we all recognise as tower defence now, Kingdom Rush: Frontiers does little more than smooth down some of the edges and add a few new patterns here and there.

That's not to say that it isn't fun, or that it's a step backwards from its predecessor. It's just that where Kingdom Rush blazed a trail Kingdom Rush: Frontiers is content to follow.

Defenders of the earth

Once again the game is all about protecting your base from an invading army. Said army attacks in waves, and you need to erect towers to beat back the waves. Every bad guy you kill nets you some gold, and you can use this to build new towers or upgrade existing ones. There are four types to choose from: arrows, barracks, magic, and cannons.

Arrow towers form the heart of your defence, spewing out projectiles that deal damage to most enemies. Your magic towers do the same, but they tend to hurt the enemies your arrows can't and vice versa. Cannons deal out slow bursts of explosive damage.

It's the barracks that pose the most interesting tactical questions. You use these to spew forth warriors that slow down and damage the oncoming force. Position them correctly and you can bring an advancing army to a halt in a corridor of violent projectile death.

Alongside your towers you have a hero at your disposal. There are three included in the game and they level-up and earn new powers as you fight. Again they're handy for slowing down advances, and they do a lot of damage if you use them wisely.

Deep towers

The deeper you get into the game the stronger your arsenal gets, and the tougher the bad guys you're facing become. Flying enemies can't be slowed down, giant bosses require all of your tactical nous to take down, and some creatures spawn new units when you've gunned them down.

Terrain can deform as well, opening up new lanes from which the enemy can attack your base. Luckily, the more powerful your foe the more options for violent retribution are open to you. You'll unlock machines that cause earthquakes, turn your barracks into schools for assassins, and arm your archers with deadly crossbows.

And everything is presented in the same gorgeous cartoon style that made the original Kingdom Rush so endearing. There's a level of polish here that other developers should pay close attention to, and a string of pop culture references and jokes that keep you entertained.

Kingdom Rush too

Kingdom Rush: Frontiers is more of the same, then, but it was always going to be, and while it never breaks new ground it never feels stale or old fashioned either. It's a brilliantly engaging game that sucks you into its world and refuses to let you go.

Does it reinvent the tower defence wheel? No, but it does clear the road of any obstacles and put a few exciting ramps in here and there, and really that's all most of us wanted.