Overall, they did a great job. Sure, the creator forgot the waterfall, for example. It takes away some of the beautiful surroundings.
But about the color of the water ... It depends on whether you create realistic scenes or not. The water itself is not blue. But sure, blue water would fit the art style itself better.
But in this scene I'm not sure if this is "Mako" or real water. I do not know. In many "Mako" scenes, it's mostly blue too.
But everyone could create their own creations if you don't like the published ones. Everyone is free to do so. I really hope that this project will be joined by a few more people who are really serious. Because the results so far have been great.