These all expire in a couple of days so I'll just do a big post:

• BioShock Remastered

  Explore an undersea city, once a haven, now a dystopian nightmare. BioShock is a shooter unlike any you've ever played, loaded with weapons and tactics never seen. You'll have a complete arsenal at your disposal from simple revolvers to grenade launchers and chemical throwers, but you'll also be forced to genetically modify your DNA to create an even more deadly weapon: you.

• Spelunky

  Spelunky is a unique platformer with randomized levels that offer a challenging new experience each time you play. Journey deep underground and explore fantastic places filled with all manner of monsters, traps, and treasure. You'll have complete freedom while you navigate the fully-destructible environments and master their many secrets. To stay or flee, to kill or rescue, to shop or steal... in Spelunky, the choice is yours and so are the consequences!

• Quake II

  You are humanity's last hope to stop the Strogg, a hostile alien race waging war against Earth. Play this military sci-fi FPS, now upgraded for modern platforms with improved visuals, new campaign content, online multiplayer, local co-op, and more.

• Duck Paradox

  Duck Paradox is a bouncing bullet precision platformer that will test your patience but reward your perseverance! Navigate the multiverse as scientist Dr. Paraducks in search of her beloved pet duck. Each of your shots becomes your worst nightmare in an attempt to kill infinite corrupted ducks. Tackle difficult-to-master trials, run after run, with the utmost quickness to earn powerful upgrades, save your duck, and repair the tattered threads of reality.