Just picked up a copy of
Galaxy Defenders and played it last night. Awesome game! I bring it to your attention, because it reminds me of X-COM in a board game format. Now, I know there is a now an board game called "X-COM: The board game", but I hear it greatly abstracts away the tactical combat side of X-COM. It should probably be called "X-COM: The Geoscape simulator board game". When I think of X-COM, I think of squad level combat. Galaxy Defenders does this in an awesome way. You can pick your agents with differing abilities. You can pick your equipment and upgrade your equipment over time. You can improve agent's skills and abilities. The alien A.I. is pretty slick for a cooperative game (there are rules on the website for a player controlling all aliens). It comes with 12 missions that can be played in a campaign format, so agents carry their improved abilities over to the next mission. Also, more missions are available for download on the website.
There will be expansions later this year that will continue the story and add cooler weapons and tougher aliens.
Here's a site with some reviews:
https://boardgamegeek.com/boardgame/138431/galaxy-defenders