Wow… Before i go back to Unity i rather jump into burning gasoline… No material editor, managed slow C# code, no support, gazillions of bugs you have to code around to get your stuff done, no source of the engine to fix things yourself, poor rendering quality, poor lighting (and poor light baking), messy animation system.
Maybe Tim would reconsider that decision, i don’t feel UWP as a threat, rather than a choice/option. And when it comes to those 30% you have to pay MS, you have to pay the same to Steam…