Piston game engine is described as 'Modular open-source game engine made in Rust' and is an app in the Development category. There are seven alternatives to Piston game engine for a variety of platforms, including Mac, Windows, Linux, Android and iPhone. The best alternative is LÖVE, which is both free and Open Source. Other great apps like Piston game engine are Pygame (Free, Open Source), LibGDX (Free, Open Source), nCine (Free, Open Source) and raylib (Free).
Pygame is a set of Python modules designed for writing video games. Pygame adds functionality on top of the excellent SDL library. This allows you to create fully featured games and multimedia programs in the python language.
Orx is an open source, portable, lightweight, plugin-based, data-driven and extremely easy to use 2D-oriented game engine. Orx is mostly written in C, but allows you to develop with it with any language that can interface to C.
Ursina makes it easier to develop games, visualizations and other kinds software. The concise API combined with the power of the Python programming language, makes life easier for the developer so they can focus on what they are making.