Ballerina does NOT force you to write "visually". You can write normal code and NEVER look at a picture.
However, after you're done, if to see the flow of your entire program (not just one function) as a sequence diagram then you can get that done.
The language syntax is "normal" syntax and has all the power o a modern language. Try it and see- feedback welcome.
Disclaimer: I'm the one who started the project and leading it as the product manager now.