M.U.G.E.N (also known simply as MUGEN) is a freeware 2D fighting game engine designed by Elecbyte, written in C which originally used the Allegro library. The latest versions of the engine now use the SDL library.
Dragon Ball Mugen is the series of Fanmade games created by different people.
It usually consist of many characters.Forexample Mugen edition 2011 contain 99 Characters and 54 Stages.
These games are developed on 2D engine but still can as awesome as you guess.

You see there are so many character to choose.I personally recommend you to try this game on which ever edition you get.

I have played it.
they are awesome games.

Indeed they are.
2011 version was the best.