Hero Engine is described as 'The only true complete development platform for online games. HeroEngine seamlessly integrates the entire client and server architecture required to operate an online game directly into the development process' and is an app in the Development category. There are more than 25 alternatives to Hero Engine for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Android. The best alternative is Unity. It's not free, so if you're looking for a free alternative, you could try Unreal Engine or Wick Editor. Other great apps like Hero Engine are CRYENGINE (Free Personal), Torque 3D (Free, Open Source), Stride Game Engine (Free, Open Source) and ENIGMA - LateralGM (Free, Open Source).
Unreal Engine is a professional suite of tools and technologies used for building high-quality games across a range of platforms. Unreal Engine’s rendering architecture enables developers to achieve stunning visuals and also scale elegantly to lower-end systems.
The Wick Editor is a free and open-source tool for creating games, animations, and everything in-between. It's designed to be the most accessible tool for creating multimedia projects on the web. Your creations can run on any device with a web browser - that means mobile too.
Stride (formerly Xenko) is an open-source C# game engine designed for the future of gaming. It comes with a full toolchain and is especially well suited to create realistic games but allows you much more!.
Cocos Creator is a complete package of game development tools and workflow, including a game engine (based on Cocos2d-x), resource management, scene editing, game preview, debug and publish one project to multiple platforms.