Anomaly Defenders could have been a case of throwing the baby out with the bath water.

In switching the action around, and dropping the tower offence template that has built the series up, 11bit risked losing everything that made the previous three games so special in the first place.

And for the first few levels that feels like a very real possibility. There's a sense that we've seen all of this before. Streams of tanks roll out of a gate, and it's up to you to build the gun emplacements to stop them from reaching your base. Or in this case your escape pod.

But then things start to kick up a gear. Each of your tower-types has a unique skill tree attached to it, and you can use tech points to upgrade them. Then there's resource gathering, cover, and potential ambushes.

After that brief scare it turns out that, while Anomaly Defenders might not be as immediately novel as its predecessors, this is still a far weightier strategic game than your normal tower defence fare.

Buttery biscuit base

Right off the bat it's clear that as much love has been lavished on the visuals here as with the other Anomaly games.

Everything glows and sparkles, beams of energy crackle across alien walkways, and shards of light protect enormous mechano-organic cannons from railgun fire.

The first lacklustre skirmishes walk you through the core of the game. Tap to place turrets in pre-set locations, earn resources to build more turrets by blasting the waves of tanks that roll down the walkways towards your base.

If you're playing on easy then the first hour or so of the game is essentially a write-off. You get too much cash, it's too easy to destroy the incoming fighters, and it's rare that your base will ever be in any peril.

Pause for thought

But shift things up to normal or hard and the game suddenly comes to life. What was a simple matter of piling forces at junctions becomes something much more interesting.

You need to hide your best weapons behind cover so they're still in one piece when the horde rolls past, and figure out which of your towers is going to do the most damage against the vehicles you're pitted against.

Here the 'pause' button comes into play. It lets you evaluate the situation, strengthen your defences where you need to, and set some of your powerful buffs to heal and help your weapons.

When you're scrapping away in easy the 'pause' button feels like an unnecessary luxury. When you're on the verge of collapse in one of the harder settings it's a blessed moment of respite that lets you consider your next move.

Go hard or go home

It's moments like that that make you realise how well 11bit has handled the flip to traditional tower defence. This is a lavish production that isn't afraid to layer on more complex ideas onto the template.

Do you drop your expensive resource gathering node at the start of the game or build some more firepower and hope you earn enough to put it up later? Do you upgrade that battery on the chance that the avenue of attack will switch, or build closer to your base?

Anomaly Defenders is a fitting end to the saga. It's not as impressive as the original, but it's still the most polished and interesting tower defence game we've seen for a good long while. Just do yourself a favour and give easy mode a miss.

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