GameDevelop doesn't even come close to Construct in terms of usability , ease of use : Too many clicks to do things that could be made in one or two. Second, it uses SFML as backend. SFML is a great library but it is not super fast in terms of rendering. I believe Constructs engine is much faster. An engine/editor must be complex in terms of what and how easily you can do with it and not how difficult is to do things. In this Construct pwns all other solutions for 2d games that exists today.