(UDK) Whilst using udk the basic format is easy to use as well as gives you basic tools to improve your scene as well as the more complicated tools are easier to use than you would think by looking at it
(Construct 2)
Using construct 2 was again simple to use once you are used to the format of adding images in but other than that its A lot like Photoshop as-well as using a similar coding style to flash.
(Frostbite 2) Looking through images, reviews and videos of this game engine showed me how highly detailed the scene's can be it looks as if you looking at a photograph of a real place which in itself makes any game using the scene that much better as-well as the other programs is simple to use and
the more complicated tools can easily be learned from simple use.