Great app! There are a few bugs, but it looks very promising. At the moment, I keep running into two bugs consistently: 1) it closes when rendering and doesn't finish the render (toggling with S key didn't help); and 2) after going into the customisation screen where you can customise the colours and effects, there's no way to return to the previous screen.
Thank you for this! I hope you keep working on it and improving it, as I'd love to buy a full license copy once it's out.