I finally got around to playing Penny Arcade: On the Rain-Slick Precipice of Darkness Chapter One (it was only a dollar last week at Steam). In the game, you uncover a mime cult headquartered at a seaside amusement park. The end boss is a Cthulhu like demon mime. (Quick review: gameplay is surprisingly fun, character design is good, but the writing is "can I click through this quicker, please?" tedious.)
It's now back to $8, but if you're looking for something cheap to play this weekend, Alice: Madness Returns is a $5 digital download at Amazon. Or if you're looking for something even cheaper, try endless runners Zombie Carnaval (99 cents) and The End (free) at iTunes.