If you've felt like puzzle games have become a bit stale and predictable over the years, with many of them using well-known mechanics to simply create variations on a known theme, you'll want to check out Death Squared. It's amazing how first adding a second person (or pitting you against yourself) to the mix and forcing careful coordination and teamwork can really liven things up. Add in some clever and sometimes diabolical leaps of faith that are necessary to discover the game's secrets and progress and it makes for one of the best puzzle games I've played in years. If you really want to push the limits of your sanity try the collection of 4 player puzzles as well, it makes for a lot of laughing, yelling, and fun.