SIO2 Engine is described as 'SIO2 is an OpenGLES based cross-platform 2D and 3D game engine for iOS, Android, MacOS and Windows which provides you all the modern game engine functionalities built-in right at its core for your mobile devices at a fraction of the regular industry price for the same type of' and is an app in the Development category. There are more than 25 alternatives to SIO2 Engine for a variety of platforms, including Windows, Linux, Mac, 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 GDevelop. Other great apps like SIO2 Engine are Wick Editor (Free, Open Source), Scratch (Free, Open Source), CRYENGINE (Free Personal) and Torque 3D (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.
GDevelop is an open-source game making software designed to be used by everyone. Any kind of 2D games can be created with it and no programming skills are required to get started. Logic of games are made using visual events.
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.
Adventure Game Studio (AGS) - is the IDE and the engine meant for creating and running videogames of adventure (aka "quest") genre. It has potential, although limited, support for other genres as well.