On a recent gaming night with friends, no board game ever made it out of the box. Instead, we spent hours playing "Keep Talking and Nobody Explodes."
This is a cooperative game involving one player on a laptop (well, any PC or Mac) and one or more partners rifling through a stack of printouts. The computer player is looking at a suitcase bomb with multiple "modules" scattered across its exterior. Each module has wires to be cut, passwords to be entered, buttons to be pressed, and more. That player must rotate the bomb on screen and describe to all the partners what it is he's seeing.
Meanwhile, it's the partners have the information on how to defuse the bomb. A printout on wires will tell you what to do based on how many wires you see, what color they are, or how they're connected. A printout on strange symbols will tell you the proper order to press buttons in, depending on which symbols are present. So on, through a dozen different possible puzzles.
The game does an excellent job of getting players to work together. The player on the computer has to have good time management and attentiveness -- some bomb modules are "needier" and can explode quickly, and different puzzle types take more "leg work" on the part of the team than others. Optimal diffusing involves keeping as many of your teammates working at all times as you can.
At the same time, all the different puzzles call on different ways of thinking. There are puzzles for people who are good at spatial orientation, people who rock at word games, people with strong memories, and more. Everyone in the team can get their moment to shine as you figure out who is best at which type of puzzle... and then you can increase the difficulty if you like by assigning different puzzles to different people.
In terms of difficulty, the game offers plenty as it is. A bomb can have 10 modules or more on it, and the range of countdown lengths factors into the challenge. The puzzles are all procedurally generated, too. Even once you progress through all the difficulty settings, the game has great replay value as different module combinations show up each time you start on a new bomb. (And even as long as we played, we didn't come close to working our way through all the difficulty settings.)
I'm not sure where the sweet spot is in terms of number of players, but I know that with 4 we had a great time for hours on end. And I'm eagerly looking forward to playing again.