eucalyptus-editor
The primary editor used to make games on the dropbear engine. It is scripted in Kotlin and is JVM first-party supported.
Other functions
To run a local play test, run eucalyptus-editor.exe play {project_dir}.
eucalyptus-editor (the editor itself) does not have a scripting interface, therefore can be run without the Java Virtual Machine. If you do wish to enter into "Play Mode" or start testing your game, you will require a form of Java Development Kit (JDK).