, the 8-bit video game featured in the Community episode "Digital Estate Planning" last month, has been approximated by game-developing fans of the show and made available as a free download on Reddit.
The game plays essentially like a Mario Bros. game, with limited options for what the characters can do, but you can play with any of the series' main characters, or else a number of extra characters or specialized variants like "Squirrel Britta." The developers are still updating, adding characters and fixing bugs on a near-daily basis, so even money says sooner than later you'll be able to play with characters like Starburns or the claymation holiday special versions of the Study Group.
Also, the more anal-retentive among you will notice that (besides having less character functionality than it did in the show) you can't die in the game--not after being attacked by hippies, not from jumping off a cliff and not (unless you've got some specialized hardware I don't) from the thirty-second timer when you get up to pee.
You can download the game for Apple's OS X, Windows or Linux.