Get Rem's Engine 
First download an IDE of your choice. I prefer IntelliJ IDEA, but Eclipse works fine as well.
Then clone or download the official repository.
Create a project with the contents of the repository. Use one of the export options (IntelliJ IDEA, for Eclipse just link all libraries :)), and create a jar. This will speed up your compile times.
Create a second project (one per experiment or game), and link the created jar into it.
Start working :)
Image of working inside IntelliJ IDEA:
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Created: 09:34, 21. Dec 2022; Most recent change: 09:39, 21. Dec 2022