GamersGate has Steel Armor: Blaze of War
for 66% off (10.20 $/€) for the next 15 hours. It's a tank sim with pretty graphics, but apparently interface issues. Reviews are mixed. I won't be getting it, but it might be worth a look for fans of tank sims who'd like to play some more different/modern scenarios than the usual stuff.
Also available for the next 15 hours is Fate of the World: Tipping Point
, at 70% off for 4.80 € / 5.70 $. This is a collection of the strategy game "Fate of the World" and all of its DLCs. In this game, you're in charge of a supra-national organisation (similar to the UNO), and your job is to issue policies to different areas of the world which address technology, development, industry, environment, welfare, etc. Gameplay itself is simple, but the simulation under the hood is quite complex (e.g., tracking several different ways of producing oil and which are affected in different ways by your policies). Different missions are available and operate on different theories (e.g., one mission assumes that there is no man-made global warming, another one assumes that climate catastrophes are imminent, your tasks vary of course between those settings). The game isn't perfect, but worth the price imho.
Also - I'm reluctant to call it a "deal" since you only get an 18% bonus, but GamersGate offers a pre-order bonus on the upcoming adventure J.U.L.I.A.
. The story does sound pretty interesting imho: You wake up from cryosleep as the last survivor of Earth's first mission to explore an extrasolar planet, you need to fix the ship, explore the planet, and find out what happened, and you're accompanied by the ship's "very temperamental" AI and by a reconnaissance robot. Could be fun, but I'd probably wait until it gets cheaper.