While searching for old Duel Masters posts on web.archive.org, I found two Duel Masters games.
These aren't the greatest of games, but it is an interesting find nevertheless.

http://web.archive.org/web/20100923061529/http://www.wizards.com/duelmasters/tcg/rothus.html
http://web.archive.org/web/20041230035303/http://wizards.com/duelmasters/tcg/dragon.html

I also found this guide on how to play Duel Masters. It doesn't cover things that were added after DM-02, such as Wave Strikers, Survivors, Multicoloured cards and so on.
http://web.archive.org/web/20051129030242/http://www.wizards.com/duelmasters/htmldemo.asp?id=mcd&link=demo

More advanced rules:
http://web.archive.org/web/20100522152126/http://www.wizards.com/default.asp?x=duelmasters/rulebook

"Cool Stuff" such as screen savers, wallpapers, puzzles, etc:
http://web.archive.org/web/20100408014940/http://www.wizards.com/default.asp?x=duelmasters/coolstuff/main

Puzzles found my Yami_Michael:
http://web.archive.org/web/20130214122152/http://wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/BillionDegreeDragon.jpg&nbrRows=6&nbrCols=8
http://web.archive.org/web/20130517144450/http://wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/DreamPirate.jpg&nbrRows=6&nbrCols=8
http://web.archive.org/web/20130214122113/http://wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/InnocentHunter.jpg&nbrRows=6&nbrCols=8

The Rothus game I have played before on duelmasters.com a long time ago but the Bolshack Dragon game I don't remember playing. They definitely aren't good but it's interesting to see what people came up with Duel Masters to promote it.

That DM online demo isn't half bad either. I used web archive to get my hands on the old FAQs and they totally work! Thank you, I already had some of them on my computer but not all of them.

Thanks for sharing, Haiken!

No problem.

If i find anything else of interest while searching the web archives, then I'll post it here.

I actually keep that english demo on the bottom of http://duelmasters.wikia.com/wiki/How_to_Play as 'English Gameplay demo', as it used to still work without the wayback machine.

Found you another one, puzzles.

http://web.archive.org/web/20130214122152/http://wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/BillionDegreeDragon.jpg&nbrRows=6&nbrCols=8
http://web.archive.org/web/20130517144450/http://wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/DreamPirate.jpg&nbrRows=6&nbrCols=8
http://web.archive.org/web/20130214122113/http://wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/InnocentHunter.jpg&nbrRows=6&nbrCols=8

Good discovery, those puzzles. I'll add them to the first post so people can easily see them.

As for the guide, I could not get the link on the Wikia to work. When I click the link, it tries to lead me to:
http://www.wizards.com/duelmasters/htmldemo.asp?id=mcd&link=demo
instead of:
http://www.wizards.com/duelmasters/htmldemo.asp?id=mcd&link=demo

Haiken wrote:Good discovery, those puzzles. I'll add them to the first post so people can easily see them.

As for the guide, I could not get the link on the Wikia to work. When I click the link, it tries to lead me to:
http://www.wizards.com/duelmasters/htmldemo.asp?id=mcd&link=demo
instead of:
http://www.wizards.com/duelmasters/htmldemo.asp?id=mcd&link=demo

I was noticing that myself. It used to work with the archive link, and now it wont work even with it. Might just end up removing it.

Tried to fix it myself, but I failed horribly.
For some reason, the Wikia removes "amp;" from the link "http://www.wizards.com/duelmasters/htmldemo.asp?id=mcd&link=demo".

Nevermind, I managed to fix it. I just replaced the link with another one which leads to the same guide.

I suspect the semicolon in the previous link was the problem.

I believe it was the &. Anyway, thanks.

Found another puzzle:

http://web.archive.org/web/20140514131140/http://www.wizards.com/duelmasters/puzzles/puzzleEngine.swf?stgImage=images/GhostTouch.jpg&nbrRows=6&nbrCols=8

Ah, that might have been the cause indeed.
No problem.

I found a trove of interesting things this time. Screen savers, wallpapers, colouring books, lots of puzzles, a quiz to find out which civilization you are, rules from above DM-02, etc.
http://web.archive.org/web/20100408014940/http://www.wizards.com/default.asp?x=duelmasters/coolstuff/main
http://web.archive.org/web/20050912233117/http://www.wizards.com/default.asp?x=duelmasters/rulebook

Yup, have had those backgrounds saved a long time. Theres also a few http://web.archive.org/web/20060415203113/http://www.wizards.com/duelmasters/docs/DM_EvoFAQ.pdf files of the FAQ's as well.

edit:And any of those rules should be on the individual cards ruling page already.

The information previously in the "Creature profiles" makes up a lot of the info in the story on race pages.

I made this image earlier because of Shobu and the coloring book.

I'm glad these pages were saved in the Wayback Machine. I'm having lots of fun looking through them.

Found an older link which listed all available Creature Profiles. The newest version of the link didn't list them.
http://web.archive.org/web/20090602124043/http://www.wizards.com/default.asp?x=duelmasters/creatures

Wow, you have done some digging! I didn't know about the existence of those puzzles. What an lovely way to spend your Sunday solving those and determining a civilization for you!

Wayback Machine is a great way to uncover cool stuff that would have been lost without it.

Sadly a bunch of the site is still broken, but the card database is completely untouched.