It's called Strudel, a live coding platform for music (with Hydra for the visuals), and it is a lot of fun! My code there is caotic spaghetti, I threw a bunch of ideas on the wall at the early days and then could only came back on the last day to try and stitch it toghther...
But 've found Strudel to be quite intuitive and easy going, really (if you like coding, of course). I'm very glad you liked DOOM, thank you!