As for a game engine I will recommend trying Unreal 4 it's a better engine for artist, however Unity is just as good a option although with less control over things than Unreal.
Well, Unreal 4 has Blueprint, if you have no intention of learning a real programming language like C++/C#, and actually can get on with the Blueprint system (I found it not really useful, many did find it good), it is a more artist friendly engine in that sense.
BUT: Unreal will quickly drown in MANY more options than Unity does. While that sounds like a pro (and it is, Unreal is always slightly ahead on features compared to Unity, as long as the features fit "the Unreal way of doing things" (see forward renderer still missing in Unreal last time I checked)), it is also a con at the same time, especially for new users.
The UI of the Editor is quite cluttered compared to Unity, and many of the additional options make no sense until you really dig into the documentation and look up what they do (well, that is also true for Unity to some extent).
Then there is the documentation. As long as you are going with Blueprint, its all good. I still would rate Unitys documentation higher, their online API docs are really brilliant. But Unreal documentation for Blueprint is quite close, once you get your head wrapped around the indexing.
But the documentation for the C++ part is just lackluster in comparison. Granted, that might not matter to the TO, but it needs to be said: Unity has the better API documentation for what that is worth.
Lastly, AFAIK the TO is talking about mobile 3D games. Here, the positions are actually reversed, with Unreal doing the catch up. I really am not comparing features or performance here, just the plain fact that Unity nowadays is the default mobile 3D engine for many, while Unreal 4 is certainly also used a lot. Its just not as widely used in the mobile space.
Might have to do with the pricing options, Unity being in the mobile game for longer, inertia of mobile devs or whatever.
Still, when it comes to developing mobile games, Unity would be the default option, with Unreal 4 being a close runner up for more ambitious devs.
And yeah, I am a programmer, so I do not rate the presence of a visual scripting system just as high as others (don't get me started on how they made C++ into the unwanted stepchild for Blueprint). Even if I would, I'd say you can get multiple different visual scripting systems for Unity starting at about 25-50$ from the Unity asset store, and some of these are actually quite good. As tightly integrated into the engine as Blueprint? No. But still, its an option.