I'm just here to put my two cents in.
Sometimes problems can arise from overlooked object settings.
- Have you checked that RBC is initially visible?
- I see that RBC speed is set by Bg_speed. Are you sure that Bg_speed is not 0?
- Are the RBC's being destroyed outside of the layout (or something), because if Total_RBC has a value over 100 then they don't spawn
Also, keep in mind I don't really know everything, (partly because I don't have the project to mess around with, but if you don't choose to share it that's also fine) and I am trying to make the best out of what I have.
What I also suggest is adding the browser object to your project, then inserting an alert between your actions so you can see exactly if things are running or not. It will help you a lot with overall debugging.