Does it crash in other applications that extensively use the GPU?
How does it crash? I know you said it crashes your PC and auto-restarts, but does it do a full shut down before turning back on?
It could be just an unlucky GPU or it could be power delivery issues, but I doubt it for such a lightweight game. You can always try to set limits that puts less stress on the GPU as a test like setting an fps limit or temporarily setting your display refresh rate to 60Hz if not already.
If you're comfortable doing so, you can also temporarily limit the power the GPU draws by lowering its power limit or downclocking/setting it's clock speed to the reference.
I'm not certain if it's still an issue today, but I've seen earlier this year Windows Update completely overriding whatever Radeon drivers you installed regardless if it was up to date or not, which caused intermittent system crashes. Check Driver Updates in Windows' update history and see if there's an AMD dispaly driver automatically installing itself.