I jus tried it and it ran perfectly for me.
What if you reboot your computer? Some games and demos use the system multimedia timer to calculate its timing for the animations, and that can become very inaccurate resulting in extra low fps's or blocky animations if the OS is been running for several days, because that timer measures the ms's elapsed since the OS boot.

This didnt work, i also installed direct play to ensure a legacy device was here to avoid problems but it didnt work.

Edit - i was able to run the game fine with this https://github.com/narzoul/DDrawCompat - althought the game sometimes closed itself to desktop, perhaps a bug of the game or not, i thought this could give you a hint of what the problem could be.