From above info., For 2D games, Monkey-x wins. For 3D games, UE4 wins. What is the role of UT? Will UT be used by those with huge investment in the past, or by the asset creators only? I found that most of useful functions can only be found in Asset store, not in the tool itself. Have UT already become bloatware? Besides license fee, it seems that we need to consider how fast bugs can be removed during each update too.