Download and play !
If you played the game some years ago, you surely expect to see it been shown right here.
But yeah, Unity doesn't support the web player anymore (and it's not a recent issue).
As the game is working on the last Unity version (2021), it requires a WebGL's export and adapting the code of the game...
I lack spare time for this, so I suggest you to download and execute the game on your favorite OS (those are standalones, no installation required):