Unreal Vs Unity 5 for mobile 2d games - is unreal to powerful?

I am a beginner at programming and especially game development. I finished courses for android and iOS with teamtreehouse online in order to learn how to make mobile apps. However I am wanting to make mobile games, and that means I have to pic up a game engine.

I am planning on starting with simple 2d games (like you tap and something happens) and after going trough many pages of Unity vs Unreal it seems that Unity is better for mobile 2d game development.

According to some of the pages I read- Unreal is more for 3d gaming and can be to powerful (take up memory) for simple games.

However I do feel that I would like to make 3d games at one point (possibly for pc )and unreal sounds more appealing because of that.

What do you all think?

Is unreal just to powerful to make simple 2d mobile games and I should learn to use Unity? Or is Unreal capable of being lightweight enough to be used for simple mobile 2d game development?

ps games i would consider simple (relative to other games) and that are similar to the games i would like to start making include: flappy bird, bird climb, Guess the Brand, possibly panda pop, ect. You know games where you tap and something happens.