Consider checking out the Godot Engine. I reviewed it a while back, as well as an updated video when version 2.0 was released. It's an open source, C++ powered 2D/3D game engine with a full editing environment. It is certainly worth checking out.

Why do I suggest Godot over UE4? Simplicity, open source, being more generalized (UE4 can be used for a lot of things, but at it's heart it's very much a level based FPS engine). There is nothing wrong with UE4, but for a single developer it's often massive over kill, and you've effectively got to learn the meta language they have layered on top of C++. Of course, it's a perfectly acceptable option, just realize it's a pretty massive undertaking.

What makes you think Unreal Engine 4 is not the right choice?

There are PLENTY of reasons why it wouldn't be, its a fantastic engine but rather large and thus with a steep learning curve... but I would like to find out what makes YOU think it is not the right choice, given you would feel right at home at least seeing how it uses C++ for scripting.

Of course, seeing how the games you linked are mostly 2D / GUI elements with some basic 3D worldmap in the middle, I don't think you need much of an engine to get up and running. You will mostly need capabilities to iterate on the UI quickly.

I think other people will be able to give you better advice when it comes to writing from scratch of with the help of low level frameworks. I do think UE4 will be a good choice given you find your way around it in due time. I found the UI Tools in UE4 quite good to work with.

Gian is right. Also the framework is just and extension of tools that are pre-made same with engine. The idea behind any framework is this tool was created with this style of game in mind but that does not limit you on extending the tool for other styles. Its like looking at your clothes and saying that I only have things for Monday. You might have brought the clothes for an event on a Monday but that does not limit you to wearing them just on Monday. When talking about tools you can use what you have or come up with other tools. Its basically that simple.