A sadlet is a short game, light in puzzles and challenge, with a heavily emotional (if usually sparse) plot and a tragic ending. Jason Rohrer popularized the concept with his games Passage and Gravitation.
“Frankly, what it looks like is that the IGF judges have no idea what measure to use. Some went by their personal likes and dislikes, some reviewed the games like a fucking Kongregate player with an attention span of six seconds, and some just didn’t like a game and latched onto whatever failure they first saw in order to explain their hate. That’s why the IGF renamed ‘Innovation in Graphics’ to ‘Excellence in Graphics’ (and will soon rename it to ‘Good Graphics’) and Nuovo will become Jason Rohrer’s Sadlet Award.” -Zaratustra