Get two card games for FREE! Enter your email for a print-and-play edition of Escape from the Aliens in Outer Space and both a DRM-free digital edition and print-and-play edition of Card City Nights. If you'd like a Steam key for Card City Nights, just buy the bundle for $1 or more.
Card City Nights is a lot of fun, and although it's not a particularly deep game, you can't beat free. Steam says I have 26 hours on record; I think that's pretty good for a single player card game without multi-player support. It's available (along with Escape from the Aliens) on the Humble Card Game Bundle by just entering your e-mail address.