A PC port exists and it runs beautifully. Nintendo has taken it down repeatedly.
A decompilation project recreated Super Mario 64 in readable C code, and the result was a native PC port that ran better than any emulator, and yes, in a browser.
Nintendo is the most aggressive rights holder in the industry. The project was removed, the ports hosted from it were removed, and the pattern has repeated every time a mirror appears.
This is the clearest example of why the viral lists are misleading. The link works when you see it and is gone when you go back to it.