When it comes to last year's amazingly deep strategy reboot of XCOM, 2K and developer Firaxis seem to have a "if it's not broke, don't fix it" mindset. Enemy Within, the quasi-expansion/standalone doesn't really change much - it just gives fans more. More soldier classes, more enemies, more missions and even more ways to take out the alien scum. The result is unquestionably the definitive version of one of last year's most must-play experiences; even if they didn't fix some of the small nagging problems.

If you played Enemy Unknown (and if you didn't, you're really missing out), you're bound to already be familiar with the basics here. You alternate between commanding a squadron of soldiers in turn-based combat against a threatening alien invasion and managing the resources needed to train and develop new technology for the effort. Not much has changed for Enemy Within but the biggest addition is the new currency system known as Meld. Essentially a way to fast-track a soldier's development, Meld allows you to easily give your soldiers the boost they need to take on enemies. With enough Meld, soldiers can jump higher, have better defense against alien mind melds and even sense enemies when they can't be seen.

"...lose all of your best soldiers if you don't plan everything..."

Meld offers a huge change to how you'll strategize on the battlefield, and it's even more heartbreaking when you lose the soldiers you've poured so much effort into building up. The threat of perma-death once again hangs over your every move, and you're going to lose all of your best soldiers if you don't plan everything out accordingly. It was very tempting on multiple occasions to put most of the effort on my top guys, but those efforts met a quick end, it's when you take the time to plan out your moves and script your attack that you'll get just how rewarding this game can be.

Also new to the series is the addition of the MEC soldier class. The MECs are pretty much exactly what they sound like, giant suits of armor for your soldiers that pack one hell of a punch. They may lose some of their mobility, but they often pack huge Gatling guns and explosives to take out large amounts of enemies. A bit of a tip, you'll find it's worth it to spend a decent amount of Meld on the MECs, since making them last longer and just a bit more mobile will allow you to use them as scouts, allowing their damage-sponge style armor to out the hiding spots of your enemies.

"...you're going to both crave...and fear them. "

Of course, this is XCOM and you wouldn't want things to be too easy. Your alien enemies have discovered mech-suits as well and their new Mechtoid class has the potential to completely disrupt your strategy by powering through pretty much all of your defenses. Clashes between your MECs and the Mechtoid suits are some of the game's most epic moments, and you're going to both crave...and fear them. The same goes for the seeker enemy type, which can cloak itself appear right in front of ANY of your enemies, yes including snipers with almost no warning.

Though you can play Enemy Within on its own, it's also available as an expansion to last year's game. While it's fun to integrate the content in with the older stuff, you can't use the Enemy Within features in an existing game - you'll have to start one new. It's a bit of a drag, but the content here is worth it, and I haven't gone back to my original game since starting Enemy Within.

If you loved last year's XCOM: Enemy Unknown, you're sure to enjoy the new edition, Enemy Within. Not much has changed, but the developers have added new content including new enemies and a new soldier class to keep fans on their toes. They may not have fixed some of the nagging problems from the original, but those pale in comparison to how awesomely rewarding it still feels to complete a mission with your best soldiers still alive.