There is a new add-on for creating Metroidvania style games using the Godot Game Engine, MetSys or the Metroidvania System 1.0. This toolkit makes it easy to Metroid and Castlevania style 2D games by providing a new set of map editing tools. This tool requires the most current (beta only right now) version of Godot, Godot 4.2.
The system is described as:
Metroidvania System (abbrevated as MetSys) is a general-purpose toolkit for creating metroidvania games in Godot game engine. It helps with map design, navigation and presentation, tracking collectibles and provides basic save data functionality related to the system. Its components can be used independently, even for games that aren’t metroidvanias.
To use it, copy “addons/MetroidvaniaSystem” to your project and enable the plugin in Plugins tab of Project Settings. Note that enabling the plugin for the first time requires editor restart (it will be performed automatically).
The addon includes a sample project that shows how to use it.
You can learn more about the MetroidVania System or Metsys for short in the Godot game engine and see it in action in the video below.