It's pretty cool in that it appears to have some tripwire-esque stuff so that you get useful logs when malware does try to do dodgy things in their sandbox. It sounds like it can alert the user with something like, "your browser might be compromised, start a new session" and everything is captured/saved so that admins can come back later to do forensics with the session that went bad.
Sandboxie was one of the original Windows application virtualization options 10 years ago.
I was hoping something would become the 'Docker for Windows' but these programs are being snapped up by software security companies.
He absolutely tears apart application sandboxes like "Sandboxie".