One of the game prototypes made during Double Fine's annual Amnesia
Fortnight game jam is going to see formal release, the action/puzzle
title Hack 'n' Slash.

BattleBlock Theater is a massive game of platforming, puzzling, cooperative, and competitive fun. Matt Miller makes his argument for the game's inclusion as one of 2013's top 50 games. 

I was blown away by this hidden gem of a puzzle game when I reviewed it in May, and I'll be banging the drum for its inclusion on our year-end list.