many years ago...(AN AGE AGO lolz) I used to edit DooM maps for fun. My best creation was Bowser's Keep though...I poured my soul into that level creating it lolz...one day I'll have to post a screen shot of what it all looked like...lolz. It was actually pretty good for what it was I also had a very beta version of Ganon's Tower in mind too lolz. Gawd I wonder what I ever did with all that stuff lolz.
WADs are add-on content and can be downloaded from the modifications page at www.srb2.org. SRB2 stands for "Sonic Robo Blast 2" and is a fan game based off the Sonic the Hedgehog Genesis games and is free to download for the computer.