Occasional crashes when resizing window

[JSKitty]

The sandbox is intended to scale 'on-demand' to how the user shapes their window: adding X/Y coords when the screen exceeds the world space, however, when particles sometimes spill into 'newly-generated' screen space, there can be out-of-bounds panics.

Likely an issue with the on-demand screen space generation, and likely very easy to fix. (when I'm not dead sleepy). 💤