Right now I mainly make apps and games with html + javascript no frameworks just code but I need a serious engine to really make what I need to make. How long does it take to learn Unity to make games like temple run or 1st person shooters. 4,6,8 month’s? I have been trying other engines like Construct which is easy to learn but runs slow as F$ck on android with even the simplest games.
I suggest you download unity and buy a complete project on https://www.assetstore.unity3d.com/ like this one https://www.assetstore.unity3d.com/en/#!/content/12245
I made simple unity racing game in about 2-3 weeks.
You learn Unity, it will take about 3 or 4 months.
I figured its going to take a while to learn I am so used to visual rapid programming tools I will have to change my mindset to work with Unity. I am going to control myself and not rush learning it.
One month for 2D games and 2-3 months for more complicated 3D games. Unity is great 
Well, I don’t think that you can comment over it in short I would say everything requires practice you can learn unity in 2-3months but what left would be how you implement things on !
Hello,
I started Using Construct 2 on January of this year (2014), I was able to make a puzzle game with it in four months, it is a great tool for making a very rough sketch for a project, but to be honest it actually does run extremely slow on handheld devices for the simplest actions, but indeed it was my gateway to gaming and now im addicted to creating Android Games. I am not a programer as I am used to visual scripting, I moved on to unity and since “may” I made two Games that are almost complete now, A Breakout Game and Bubble Shooter Game, I did not buy any ready game kits, actually there is a combo that works pretty well:
I got Playmaker “Tool for visual Scripting” and 2DToolkit “A great tool for sprites and UI”, these two work together flawlessly inside Unity3D and they are like Contruct 2 on mega steroids, performance is really good and you can almost do whatever you can think of using these two. This is like using Construct 2 Inside Unity with 100x better performance and much more capabilities.
I hope this helps and good luck with your adventure.