Overland's gameplay is smart, deliberate, and addicting. Best of all: you can download and play it on your PC via the game's "First Access" program at http://overland-game.com. This up and coming indie title, developed by Finji, already shows a lot of progress, and I'm excited to see where it goes next.
"The Experimental Gameplay Project began as a student pitched project at the Entertainment Technology Center at Carnegie Mellon University. The project started in Spring 2005 with the goal of discovering and rapidly prototyping as many new forms of gameplay as possible."
Another Let's Play series I'm doing for the Something Awful Forums. I played the pants off of these free prototypes in high school.