Impulse store currently has some great titles at deep discounts.
Stardock-published games Sins of a Solar Empire (with Entrenchment) and Demigod are both only $20. Meanwhile, the economic real-time strategy sim Dawn of Discovery is $25. There's plenty of other deals, including World of Goo for $10, so try not to spend those last fleeting days of summer inside. We dare you.
[Via Big Download]