While in Naha one day during our Okinawa trip, we went to Helio's - a pub and microbrewery. They had five craft beer options (although they were out of the two I really wanted to try), one of which was a goya beer. We can find goya (or bitter melon) in Nagoya, but it is really popular in Okinawa, and shows up in a number of dishes.
I've tried cooking with goya before, and I can't say that it turned me into a bitter melon fan, so I was a bit hesitant to try the goya beer. We finally caved though and bought one in the airport before our flight home. It was fine, and didn't have much of a distinguishable goya taste, but I'd still probably go for one of Helio's other tasty options!