According to the mentioned environement the line:

<embed src="http://eoinmurphy.netfirms.com/flash/$game.swf"
[download]

will be evaluated to:

<embed src="http://eoinmurphy.netfirms.com/flash/http://eoinmurphy.net
+firms.com/cgi-bin/game.cgi?Tetriswm.swf"
[download]