Havok AI
Havok AI is a runtime SDK for programmers and designers to create pathfinding, pathfollowing, and navigation mesh generation for dynamic environments.
17 Alternatives To Havok AI

AutoDesk StingRay
AutoDesk StingRay is a game engine that comes with the support for Windows, Linux, PlayStation 4, PlayStation 3, Xbox 360, iOS and Android devices and uses Lua Scripting Language.
Cocos2d-x
Cocos2d-x is an open-source and cross platform open source free 2D game engine for mobile game development known for its speed, stability, and easy of use
GameMaker
“With GameMaker, I went from no programming knowledge to full-time developer in 2 years!” Seth Coster - Butterscotch Shenanigans - Crashlands. “GMS 2 is absolutely amazing and I cannot get over how great this software is to use”.

Gideros
Clean OOP approach. Gideros provides its own class system with all the basic OOP standards, enabling you to write clean and reusable code for any of your future games.

Unreal Engine
Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.