In communities for the Murderbot Diaries series of books, I sometimes see this game mentioned as a good fit for the feel of that universe. What I've seen in clips of playthroughs bears that out; I bought the game a while ago but haven't gotten around to actually installing it yet.
Anyway, I just wanted to shout out the Murderbot series as something that folks may be interested in if they enjoyed this game's world and are looking for something to read.
I hadn't heard of Kate before, so I can't offer much hands-on advice. I dug around and found a "handbook" here: https://docs.kde.org/stable5/en/kate/kate/index.html
Unfortunately it does look like you need to define a project to compile/run anything, which appears to require manually creating a
.kateprojectfile in the directory as outlined here: https://docs.kde.org/stable5/en/kate/kate/kate-application-plugin-projects.html#project-createI had exactly the same problem when I moved from languages that were interpreted or combined the IDE and runtime environment into one, and starting to use languages which had their own external compiler. Unfortunately, open source project user documentation is often terrible for beginners (what I found above for Kate seems to be no exception), and IDEs often seem to be written by people who don't really expect anyone to actually use the included build options (to be fair, most folks seem to like using their own separate build utilities, so probably this is often the case)
If you can tell us which compiler or interpreter you're using (e.g. gcc, clang, Python), someone can probably tell you how to compile and/or run a single-file program from the terminal with a fairly simple command.