Get a better look at the upcoming expansion XCOM: Enemy Within during this developer walkthrough, which showcases a lot of the abilities you'll be able to use to your advantage against the invasion.
We're first shown off the new hydro-electric dam map, where the MECH and new genetically modified Sniper are let loose. The new soldiers quickly dispatch the first wave of attacking aliens, with the newly improved Soldier and his mental shielding taking care of the psychic alien hiding in the shadows.
The gene-modded units have new armor, but its merely a cosmetic change. That said, the troops look to add a new dimension to XCOM's gameplay that will make playing feel fresh all over again. The new enemies should also keep you on your toes, but we'll still have to wait until Nov. 12 to find out just how challenging this add-on really is.