The best thing about Niagara has to be the moving water mechanism. When the game is set up, it looks stunning, and adult and children alike are fascinated by the way the water really moves along and flows over the edge of the waterfall - along with any unfortunate boats that get too close to the edge. Components are increadible and the gameplay is not just for children - it is actually a good game of planning and calculated risk-taking.
This was my husband and my first exposure to Eurogames. It is a great introduction game because the rules are simple, and yet you need strategy to get the stones while avoiding the river. Because of the changing river I wouldn't say the game is predictable, which is good.