I had positioned my grenadier in a flanking position when an alien appeared from its hideout. Suddenly, my most experienced soldier was in a vulnerable position. A few turns later, he was blasted away. Rest in peace, Captain Jonas Wolf.

Welcome to XCOM 2, a turn-based tactical game that requires you to harvest resources, research new technologies and send troops against technologically more advanced alien enemies.

XCOM 2 takes place 20 years after the events of its predecessor, XCOM: Enemy Unknown, in which humanity lost the war against the alien invaders. Now, humans are subjugated citizens on their own planet.

You are again the commander of XCOM, an elite paramilitary organisation which used to fight against the aliens. XCOM is now a resistance force and you must work against the odds to defeat the alien occupiers.

Working with limited resources, XCOM does not even have a base. Instead, you and your troops call Avenger, a salvaged alien aircraft, your base. Inside, you need engineers to clear rooms and build new facilities, such as power relays and laboratories. You also need scientists to research new weapons and technologies. And you need to recruit more soldiers.

From where you start, you need to scan for resistance forces in other regions. The more regions you uncover, the more personnel you can recruit. Plus, you get more supplies and intelligence data.

But resources are scarce and you need to make the right decisions on what to build or research. At times, you have to research alien technology to advance the storyline.

The storyline is intriguing and the turn-based combat gameplay addictive. You will also find twists along the way - you will learn of an Avatar Project which has a countdown "clock" that ticks down relentlessly. Once this project is completed, you lose the game.

This clock can be pushed back through doing specific missions, such as destroying an enemy base, escorting a VIP to safety or retrieving a highly prized artefact.

Before each mission, you need to select a squad of between four and six soldiers. Make sure the four different soldier classes are selected. The ranger is the reconnaissance unit, the grenadier handles the heavy weapons, the sharpshooter is the sniper, and the specialist is the tech expert with a drone that can heal or attack.

As you are now part of a guerilla team, you have the advantage of concealment at the start of each mission. So it is imperative to place your squad members in advantageous positions, such as high ground. Yet at the same time, you must avoid enemy detection.

The game graphics are superb, with beautifully rendered environments and each soldier having his own unique facial characteristics and voice. The voice acting of the lead characters during the cutscenes is outstanding.

With the uplifting soundtrack and realistic combat audio, there is almost nothing to fault about this game. Well, maybe some minor graphical glitches, like a soldier's rifle "sticking" through walls, but I am nitpicking.

• Verdict: Words almost cannot describe how addictive the entire research or build mechanics and turn-based combat gameplay of XCOM 2 are. Simply put, it is my pick for game of the year.