Goa is not a kind of music.
Goa is a district in India at the sea which is very popular all over the world, because alot of young people travel there, do drugs, make parties and have fun. Because for some months some special kind of Trance was very popular there, some people tend to call that music "Goa". But at the beaches of Goa people listen to all styles of electronic music, so the term Goa means nothing at all.
Goa, is definitely not some special kind of trance, it's complete New Age music that the place must have had an effect on the name...