There's some very exciting news today, with Unreal Engine now completely free, subject to a 5% cut of gross profits if your app makes over $3k. It's available for PC and Mac, with source available for Linux. This will be a serious challenge to Unity as the free version of Unity lacks some advanced features, especially lighting, whereas Unreal Engine is unrestricted. https://www.unrealengine.com/blog/ue4-is-free There's a guide here for current Unity developers, explaining how to migrate from Unity to Unreal Editor: https://docs.unrealengine.com/latest/INT/GettingStarted/FromUnity/index.html I'm 3 days in to development of a new iPhone game in Unity, but I'm going to experiment with UE tomorrow to see if it's worth switching. I dearly love Unity, it's a real joy to work with, but more and more I find myself writing complex shaders and scripts just to create visual effects that are built in to the engine but locked out of the free version. And I have no problem with Unity doing that, it's perfectly fair and I thank them for giving us the free version. But if a rival is going to offer a product as substantial as UE, feature-complete and free, then I'm certainly interested.
I've spent the evening with UE and I'm running back to Unity. I don't know about the PC version but the Mac version isn't ready for primetime yet. I know it's quite new so hopefully they'll work on it some more. A lot more. Currently, nearly everything fails. Create an empty project and add a Player Controller... fail. Plus this is personal taste but the viewport camera controls are utterly awful. Keep in mind that I use Unity and Blender every day, two apps that are known for their poor viewport controls, and I get on just fine with those. UE's controls are so bad that they even have one way of zooming the camera in 2D viewports and a different way in 3D viewports. Oh and the W, E and R keys for move, rotate and scale, sometimes work and sometimes don't. The quad view doesn't track mouse movements so to switch from one view to another you have to either left-click (which can mess with your selection) or right-click (which brings up a menu that you have to dismiss). I could go on... But, bottom line, I didn't like using UE at all. Unity is wonderful in its own right, but compared to UE it is beyond words. UE is an over-engineered mess that doesn't work. All of this is on Mac remember. I'm sure the PC version will work a lot better.
Yeah I watched the live announcement earlier. Makes the UE4 release redundant in my opinion, for Mac users anyway, who have what seems to be an alpha version of it that crashes all the time. Unity is a million times nicer to work with, and with the price point for pro features now dropping to a very attractive $0 it's a no-brainer. Can't wait to finish up my current project and get started with something in Unity 5!!