Video game franchises live on within the walls of publishers primarily for profit, but the pixilated heroes of fans’ youth continue to resonate because of nostalgia.

Over the past decade, a generation of bedroom programmers grew up, and many have taken to recreating childhood favorites in their own voice. Like a cover song, these free remakes, demakes and remixes are tributes that will ignite a spark in the nostalgic fan and a cease-and-desist letter from copyright holders.

Remakes

Fan remakes have a history of being canned because of cease-and-desist letters (as was the case with the much anticipated 3D “Chrono Trigger” recreation) or development problems (“Black Mesa Source,” a “Half-Life” remake that has been in the works for nearly five years). There are a few that surface and brilliantly update an old fan-favorite, such as the recently updated “Streets of Rage Remake”: an 8-year-old passion project that tweaks the beloved Sega beat’em up series with 19 playable characters, 103 stages and a level editor that allows others to add to the project. However, there is a chance it will be taken down by Sega. Last year, Sega removed (though the website still exists) the download link to the stunning HD fan remake, “Sonic Fan Remix” — a game which many fans considered superior to recent “Sonic” titles. Even Metroid and Link have been given updates in fan projects that updated the Gameboy versions of their respective series with improved graphics and sounds representative of their Super Nintendo incarnations.

Demakes

Atari 2600 graphics were once thought to be state-of-the-art for home consoles, but people weren’t impressed with last year’s “Halo 2600” because it was pushing boundaries graphically. The title, developed by a Microsoft employee, took the popular Xbox franchise and reimagined what the game would have been like if conceived two decades earlier — a so-called “demake.” These demakes take an established game and recreate them in a way that emulates hardware from an earlier time. Demakes of “Silent Hill,” “Team Fortress 2” and “The Legend of Zelda” emerged after the indie developer community at tigsource.com held a competition around the concept in 2008. Since then, the idea has carried on and inspired demakes of current acclaimed titles, such as an 8-bit “Left 4 Dead” and “Portal” reimagined entirely in text and grey blocks (“ASCIIpOrtal”).

Remixes

Many video game mash-ups were never meant to be, but that hasn’t stopped curious programmers from experimenting with putting iconic characters in a different franchise’s world. Last year’s popular “Super Mario Bros. Crossover” is an excellent example. It’s a faithful recreation of the original Nintendo title that lets the player select characters from other Nintendo classics, such as “Mega Man,” “The Legend of Zelda,” “Contra” and four others. Each character plays exactly like they did in their original title, making for a surreal experience as you try to crush Goombas with Simon’s (of “Castlevania”) lackluster jump. A more enjoyable alternative is “Super Mario Bros. X,” an ambitious project that blends all of Mario’s 2-D titles together with elements of other Nintendo games (Link is a playable character), two player co-op and original power-ups. Fighting game fans and pop culture junkies will find much to love in “M.U.G.E.N.,” a fighting game program that lets players build and import their own characters and stages, and tweak rules. You can do anything from staging your own “Mortal Kombat” vs. “Street Fighter” tournament to having SpongeBob and Homer Simpson beat Peter Griffin and Michael Jackson to death. The best downloadable character, however, is Chuck Norris, who can defeat an opponent in one move by summoning a Death Star that crushes whoever stands below.