Regret

Regret was created for Jason Rohrer's game design sketchbook, a monthly project for the online publication The Escapist. Without giving away too much info, which would spoil the experience, the gameplay concept is based around this idea:

Regrets often center on mistakes that were unavoidable at the time. Though you can learn from each mistake that you make, it's not clear that regretful thinking is valuable. What you learn by reliving a regrettable event may not end up being helpful next time you're faced with a similar situation in real life. Regrets can bog you down as they accumulate over the years, and their net effect can become mentally paralyzing.

This is played out in a short maze filled with blue orbs, animals and different types of food, much like an entirely new twist on Pac-Man in an obstacle course. Based on the way the player deals with mistakes in the past, the possible "score" will change.