I'd like to create an interesting mobile game (I hope it will be really ineresting). There are two best tools on the markeT: UE4 and Unity3d. UE4 has an attractive interface. This interface is very intuitive to understanding. Blueprints are also very intuitive to understanding. But, UE4 is totally not ready for multiplatform's development: Android's support is VERY bad :(
Unity3d is much hard to understand, Unity3d requires much stronger programming's skills, iterface is ugly, not intuitive etc. But Unity3d is really works on almost every mobile platform and for almost every mobile device on the market.
so, does it make sense to "play" with game's prototype in UE4, quickly create and test main logic (Blueprints are great and easy to use), then, after I'll sure my idea is really interesting & attractive for players, move art assets to Unity3d, coding Blueprints's logic in C# etc???
Unity3d is much hard to understand, Unity3d requires much stronger programming's skills, iterface is ugly, not intuitive etc.
Thats like YOUR opinion man. MY OPINION is that UE4 interface is bloated and slow and unity's has just what you need and no more. Both are infinitely modifiable so either one can be fit to suit almost anyone's needs. So not a good reason to choose.
so, does it make sense to "play" with game's prototype in UE4, quickly create and test main logic (Blueprints are great and easy to use), then, after I'll sure my idea is really interesting & attractive for players, move art assets to Unity3d, coding Blueprints's logic in C# etc???
So this all depends on who you are but in general if your not much of a programmer than sure it makes sense to use the excellent UE4 blueprint system. There are solid visual scripting tools in Unity that you can buy though. So thats not really a good reason to decide on which engine to use for prototyping.
I dont see any reason if you prototype out your game in blueprints to switch back over to unity. If you went through all that trouble to learn UE4 and the blueprint system. Just build your game that way. Same goes if you prototype your game in unity.
But, UE4 is totally not ready for multiplatform's development: Android's support is VERY bad :(
Sir/Bro... at the speed at which UE4 is churning out new features by the time you even get halfway done with your prototype my guess is android support will be pristine. (dont hold me to that just a guess)
Ok so if you are just wanting to make a game thats my answer for you ... HOWEVER if you are going to be or have plans to be a programmer my alternate advice is whichever you choose do not use any visual scripting period. Learn the ways of your craft by doing and learning from others.
If your end goal is to become a programmer and you want the easier start go for unity C#. C# is a bit easier to get into and the iteration times on unity are next to nothing. If you have a bit more time on your hands and want to get nitty gritty go with c++ UE4... or go all the way and build a game from scratch c++.