Godot Engine

Godot Engine is a free, open-source game engine designed for 2D and 3D game development. It supports cross-platform projects and XR ideas, offering tools for physics, rendering, and scripting. The engine includes its own scripting language, GDScript, alongside visual scripting capabilities. It provides a complete development environment suitable for building custom AI agent environments. While offering flexibility and power for advanced projects, it generally requires a technical understanding for complex logic compared to purely event-based approaches.