Found these two things when browsing r/gamedev as I do a daily basis, read 'em both and found them actually really helpful. Not so much for Multiplayer maps, but more for single player maps. I thought I would share these with you guys since I know that a few of us will be dabbling in Single Player Experiences soon. Lecture slides on level design by Matt Rix. Creator of the app game "Trainyard" Lecture slides on level design by Semyon Voinov. Designer of app game "Cut the rope" - A personal favorite of mine. This site also has a lot of other resources from GDC, not all is avaliable to the public, but some are. GDCVault.com.