Mugen is a new 2-D flash fighter developed by ELECBYTE,
http://www.elecbyte.com/,and is very fun to play. This game is not too well known yet, so there are not too many add-ons to it, but I figure everyone can help each other out here on the forums.
To download character packs into your game read the instructions in the select.def folder or follow these:
-Download the character pack itself from anywhere like
http://www.esnips.com/ and
http://mugencharacters.ucoz.com/-Unzip/move them into the chars file
-Go to your M.U.G.E.N. folder and search for select.def
-Open select.def kfm
-Insert the name of the character folder with .def at the end of it, make sure it is exactly as it spelled
-Save and go back to the search results
-Open select.def data
-Put the name of the character folders excluding .def at the end
-Save and the character pack should be ready to go
Hope that helped everyone. Please post your thoughts on the game, good add-on packs, or anything else relating to this game. I hope everyone gets as much enjoyment out of this game as I do.