The beginner of the game (black) is in great favor.
Advantage of the game:
Simplicity.
The tournament rule
The 3rd move Black must make outside the zone of 5x5 intersections with the same center as the center of the whole board, the 5x5 zone is a prohibited zone. The tournament rule decrease deferences between black and white.
Go-Moku without tournament rule is solved: Victor Allis has proven Go-Moku to be a win for black ( http://www.ai-center.com/references/allis-93-gomoku.html)