So, I played this game yesterday for 7 hours straight, got so carried away. It is very good.

Pluses:
-Good atmosphere and story true to the ALIENS franchise
-Game mechanics familiar from XCOM games - deploying a squad into a map and fighting hostiles/completing missions
-Large maps that you can revisit later
-Variety of alien mutations
-Not bad soldier promotion system
-Smooth gameplay with just minor bugs after first major patch and another coming
-Marines weld doors saying "You shall not pass, fuckers!" and break weld with "Open Sesame"

Negatives:
-Somewhat small arsenal
-Aliens on missions are infinite (the game seems to be meant to be played mostly stealth and combat only when there is no escape
-Marines comment too much on everything during missions, gets annoying