The XCOM series occupies a place in history as one of gaming's most respected franchises, charging players with surviving a large-scale alien invasion.

Featuring an isometric perspective and squad-based strategic gameplay, XCOM: UFO Defence is a constant fixture on top 100 lists.

Subsequent titles haven't quite managed to replicate the first game's success, but FireAxis Games have stepped up to the plate with the latest XCOM game.

Let's get something out of the way first, XCOM: Enemy Unknown is not a first-person shooter. Instead, it draws its inspiration from the original – so turn-based tactical gameplay is king.

Players take command of the alien-fighting XCOM organisation and a squad of soldiers, travelling around the world to take on various alien threats.

A unique experience

Gamers have loads of freedom when it comes to choosing missions, with levels in the USA, China, Russia, Europe, South Africa and other locales. You'll want to help out all nations equally though thanks to the system in place, which sees countries pull out of the XCOM programme if widespread panic occurs in their region.

The combat system manages to attain that "simple yet hard to master" status, with gamers having to move each member of their squad on the battlefield. You'll want to take advantage of cover too, with some obstacles making for better cover than others.

Once you've moved your troops into place, you'll have the opportunity to attack the enemy, ranging from an assault rifle burst and shotgun blast to grenade toss and rocket launcher blast.

After you've made your moves, you'll then get to sit back and watch the aliens do their thing. And you'll encounter loads of extraterrestrials along the way, such as your standard Grey, the creepy "Thin Man" and much more.

The aliens have an array of weapons and nasty dealers of death at their disposal, such as laser-based weapons, poison gas and psychic abilities

But you'll have plenty of upgrades and items to help you along the way, thanks to the research feature. XCOM scientists are able to come up with new and improved tech by analysing salvaged alien scraps you obtain during missions.

And players are able to guide the process as well, choosing what gets researched based on the scraps at hand. So, if you'd prefer to focus on jetpacks or radical new weaponry, the choice is yours.

Your soldiers also gain new abilities as they complete missions, giving you incentive to keep them alive even though they're expendable.

And your soldiers will die indeed thanks to the difficulty level, with the first few missions starting off easily enough but quickly ramping up. Before you know it, your squad will be slaughtered thanks to a careless few moves on your part. Yep... you'll want to be as methodical as possible.  

The gift that keeps on giving

But there's more to the game than just combat and upgrades, with players able to build additional facilities, launch satellites to detect alien activity more effectively and dispatch interception flights against UFOs.

The great thing is that, for the most part, a lot of these aforementioned features are optional. So if you'd like to focus solely on kicking alien ass and upgrading your kit, then go for it.

Once you've completed the meaty story mode, players looking for more content will be pleased with the inclusion of a one-on-one multiplayer mode.

Players are given a preset budget to assemble a squad of humans, aliens or both, with neither party able to see what the other has brought to the table until the game begins.

Presentation

XCOM: Enemy Unknown might not boast the visuals of a Battlefield 3 or Far Cry 3, but it doesn't disappoint anyway. Featuring destructible environments, great lighting and extensive use of primary colours, XCOM manages to carve out a unique style.

Our only real complaint was the rather short draw distance, owing to the game's deliberate use of fog to shroud the battlefield. Nonetheless, it adds a strategic layer to proceedings, so we'll let it slide.

When it comes to the audio side of things, XCOM stands out, featuring some fantastic voice-acting and great sound effects.

A refreshing change

All of these elements combine to form a title that is not only unique in its concept but excellent in its execution.

The lengthy story mode offers tons of replayability thanks to the varied missions and extreme difficulty option, while the resource management is deep enough for armchair strategists.

XCOM: Enemy Unknown comes highly recommended, whether you're a shooter fan or strategy addict.

Score: 9.3 out of 10