Unreal Engine 4 includes a visual scripting language called Blueprint.

That website collects some of the bad examples of what people do with this system - a lot of the times, the results are the visual equivalent of spaghetti code. In my experience, this kind of spaghetti is quite normal in shipped games.

Just to be clear, any type of spaghetti (visual or code) is common in any type of shipped software product (game or not), especially ones where there is deadlines.