Bevy vs Ren'Py

Bevy is a free, open-source game engine built in Rust for 2D and 3D games, visualizations, interfaces, and other graphical applications. It uses a custom Entity Component System, with components represented as Rust structs and systems as Rust functions. The engine includes 2D and 3D rendering, a composable render graph, skeletal and morph-target animation, scene loading, hot reloading, UI, and audio playback. Its 2D renderer supports sprites, texture atlases, cameras, materials, custom shaders, and render pipelines. The 3D renderer includes lights, shadows, meshes, materials, cameras, and glTF loading. The ECS-driven UI framework uses flex-box layout and can be composed in code or scenes. Scene changes can update running applications; hot reloading currently covers scenes, textures, and meshes. Bevy targets Windows, macOS, Linux, web, iOS, and Android, and is available through crates.io with cargo add bevy. Users choose MIT or Apache 2.0 licensing, with no license fees or sales cuts. It remains in development, with possible missing features, sparse documentation, and breaking API changes about every three months.

Ren'Py is a free visual novel engine for making interactive stories and life simulation games with words, images, and sounds. Its script language handles visual-novel writing, while Python can be used for more complex game logic. Default games include menus, automatic saves, rollback, predictive image loading, and mouse, keyboard, or gamepad controls. Creators can customize screens and styles using the screen language and Python. The launcher builds Windows, Mac, and Linux games from any of those desktop systems. Ren'Py also supports Android export and can package games for WebAssembly browsers, though web support is beta and lacks networking and multithreading. It targets Windows 10 or later, macOS 10.10 or later, Linux x86_64 or Arm, Android 5.0 or later, and iOS 11 or later. Building for iOS requires a Mac and Xcode, and that support remains a work in progress. The engine is free for commercial and non-commercial use; most is MIT-licensed, with some LGPL components whose terms distributors must meet.