RPG Architect
RPG Architect is a next-generation RPG game maker with all of the limitations removed. It is designed to be simple enough for a newcomer and advanced enough for a veteran of game making engines.
 
KorGE Engine
Modern Multiplatform Game Engine for Kotlin
  Intersect
Intersect provides a complete game development suite for creating 2d mmorpgs with no programming experience
  KAPLAY
KAPLAY is a JavaScript and TypeScript game library that makes it easy to create games for the web. It's free, open-source and fun.
  8th Wall
The 8th Wall Studio Game Engine is a powerful, browser-based development environment designed to build cross-platform 3D & spatial (XR) games directly on the web.
 
JoEngine
Jo Engine is an open source 2D and 3D game engine for the Sega Saturn written in C under MIT license. It allows to develop game easily without extensive knowledge in embedded development.
 
Rpg in a Box
A beginner-friendly Game Engine that is packaged with everything you need to create games, no programming or modelling knowledge required
  Atlas Engine
This is a cross platform toy engine that is available on Linux, Windows and MacOS.
 
modd.io
Modd.io is a low-code game engine where you can play & make games all in a browser with built-in netcode and free server hosting
 
Hology Engine
A versatile game engine designed for creating 3D games and experiences. It includes landscape sculpting, a physics engine, customizable shaders, and procedural foliage generation.
  Sundown
An extendible WebGPU game and simulation engine for fun, games and research.
 
Comfy
Comfy is a fun 2D game engine built in Rust. It's designed to be opinionated, productive, and easy to use. Inspired by macroquad, raylib, Love2D and many others, it is designed to just work and fill most of the common use cases.
 
Mach
A Zig game engine & graphics toolkit, for building high-performance, truly cross-platform, robust & modular games, visualizations, and desktop/mobile GUI apps
  SGDK
SGDK is a free development kit allowing development of software in C language for the Sega Mega Drive.
  Love2D
A free and open-source framework to make 2D games in Lua
 
Murder Engine
A pixel art ECS game engine built on top of MonoGame.
 
DragonRuby 2D Engine
DragonRuby Game Toolkit is a professional grade cross-platform 2D game engine
  Three.js
An easy to use, lightweight, cross-browser, general purpose 3D library
 
openFrameworks
An open source C++ toolkit for creative coding.
 
ENIGMA
ENIGMA is a free development environment geared towards game development and compatible with Game Maker projects
  ZGB
ZGB is a Game Boy / Game Boy Color engine that lets you write your own games in C or ASM.
 
Construct 3
Construct 3 is a powerful and user-friendly game development engine without the need for extensive coding knowledge
  MEG-4
Very performant fantasy console with lots of features and multiple languages
  Oxygengine
Oxygengine is an all-batteries-included kind of engine, focused on being Web-first but slowly moving more into more platforms such as desktops and consoles
  App Game Kit Studio
Vulkan powered cross-platform coding
 
RPG Maker MZ
A new iteration of RPG Maker that let anyone regardless of skill level make an RPG
 
microStudio
microStudio is a free, open source game engine online
 
Gosu
A 2D game development library for Ruby and C++, with few dependencies and great to learn Ruby or for short game development competitions
 
HaxeFlixel
A cross-platform game engine built with Haxe
  Ambient
A runtime for building high-performance multiplayer games and 3D applications, powered by WebAssembly, Rust and WebGPU