UrhoSharp based on Urho3D now supports both HoloLens and ARKit.

I've been very curious about this engine. Maybe someday.

Source: https://mspoweruser.com/new-3d-game-engine-makes-peace-hololens-arkit/

As of July 12th 2017, Autodesk's middleware software suite usable in various game engines is no longer available. 

Stingray (originally Bitsquid) is however still available and is probably the intended replacement for the above products.  

Source: https://www.autodesk.com/content/autodesk-game-middleware

A new release of Bladecoder Adventure Engine was made available recently with some test projects and Spine support. 

I've only recently discovered Bladecoder which focuses mainly on composing point and click games. Having tried a couple of Android games made with this suite, I can affirm this can help create competent end results.

Source: https://github.com/bladecoder/bladecoder-adventure-engine/releases/tag/v1.2.7

Unity 2017.1 has been released marking the debut of a new release cycle for the game engine.

The big new addition is Timeline where cinematic content can be created by orchestrating game objects, audio, animation, etc. 

Source: https://blogs.unity3d.com/2017/07/11/introducing-unity-2017/

Leadwerks Software has released an update that features a new GUI system, IK support and enhanced visuals.

The on-going Steam Summer Sale brings the price of this engine down significantly. You can get it here.

Source: https://www.leadwerks.com/community/blogs/entry/1973-leadwerks-game-engine-44-released/