Note: There are no known MAGFest challenge pages from MAGFest 10 and before MAGFest 6.
If you don't mind emulating retro video games, these pages have retro gaming challenges easily accessible through save states:
MAGFest 6 - made of NES challenges - at http://courtwright.org/challenges.
MAGFest 7 - made of 67 NES challenges - at http://web.archive.org/web/20140719133923/http://magfest.org/m7challenges/index.html - it's on archive.org because if you go on the page without archive.org, you'll get a 404 error.
MAGFest 8 - made of 100 Genesis/Mega Drive, NES and SNES challenges - at http://courtwright.org/m8challenges.
MAGFest 9 - made of 100 Genesis/Mega Drive, NES and SNES challenges (the SNES challenges have still not been revealed, at least on this web page, despite the fact it still says it'll be unveiled on or before 10/29/2010) - at http://courtwright.org/m9challenges.
MAGFest 11 - made of Atari 2600, Genesis/Mega Drive, NES and SNES challenges (unfortunately, the Atari 2600 save states are lost) - at http://courtwright.org/m11challenges.
MAGFest 12 - made of Atari 2600, Genesis/Mega Drive, NES and SNES challenges - at http://web.archive.org/web/20150920080921/http://www.magfest.org/m12challenges - it's on archive.org because if you go on the page without archive.org, you'll get a 404 error