If you aren't already familiar with Penny-Arcade, then you are probably not a PC Gamer. Go ahead and check out http://www.penny-arcade.com to familiarize yourself with the comic. Finished yet? - Good
Penny Arcade's On the Rain-Slick Precipice of Darkness is a simplified Point - and - Click RPG. Before I go any further I'd just like to say that the visuals in this game are fantastic. It's on a completely different level than the ultra-realistic Crysis, as it's more of a comic based game; however, all of the images are hi-res and beautiful. This is a trait I've come to love with the indie games -- Braid comes to mind.
Visuals aside, the gameplay has several layers to it. There is a space bar oriented block/counter system setup that is similar to gameboy games. Fights are real-time and can get hectic when you are controlling 3 characters and their attacks charge at different rates. All the while you're keeping track of the enemy attacks so you can press space in time to block. This style of gameplay tends to keep you wanting to play more as it doesn't get boring. You can't autopilot through the combat just to follow the story as you'll die a horrible death.
The story follows a player you create as he chases a giant robot that destroyed his house. Sounds ridiculous - tho it is a comic based RPG-adventure game, so stay with it. The player eventually meets up with the main characters from the PA comic and joins with them as they uncover a sinister mystery surrounding New Arcadia.
This game is incredibly cheap and is definitely worth adding to your collection as it will provide plenty of laughs as well as hours of gameplay.