How about a little something to unwind for the evening with? A charming looking free game tickle your fancy? Fortified has apparently been around on Steam early 2016, but it managed to fly entirely under my radar. A crying shame, because it looks like Orcs Must Die spliced with Mars Attacks. Developer Clapfoot (working on the currently-in-early-access Foxhole) have opted to just give it away for free today. If you nab it on Steam between now and 11am Pacific Time on June 8th, you get to keep it forever.
I've not had a chance to try Fortified yet, but I've currently got it downloading to give it a spin once they unshackle me from my news-desk. Judging by the trailer below, it is very much in the vein of Orcs Must Die, but with wobbly martian robots and UFOs instead of oddly lovable orcs being exploded into clouds of meat. Probably for the best, really. It supports four player online co-op too, so get your friends to snag this too while it's free.
If you've never played Orcs Must Die? Well, you should probably try that too (there's a pretty good free-to-play spinoff now), but what you're getting here is a basic third-person shooter paired with tower defence mechanics. Enemies travel along a set route (which you can manipulate with barriers to some degree) from A to B, on a collision course with your chosen defensive objective. Zap them all, spend your profits on more defences, rinse and repeat. It's simple, compelling fun.
Looking at the Steam reviews for the game, a common complaint was that there was nobody to play it online with at launch. A problem that appears to have been rectified, according to Steamcharts, although I'd wager that the majority of those 130,000 'players' are bots mining the game for trading cards that will be resold for a penny profit a piece. Do your part for humankind and fight the robot horde - the card mining one - and give the game a spin. It's free.