Just point to the upstream GPL.

--- doc/manual.html.orig	Sat May  5 16:22:50 2007
+++ doc/manual.html	Sat May 26 18:53:47 2007
@@ -54,7 +54,7 @@ along with this program; if not, write to the Free Sof
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.<BR></P>
 
 <P>Blob Wars : Metal Blob Solid is distributed and licensed under the GNU General Public License. You can read
-the full license by clicking <A HREF="LICENSE">here</A>.</P>
+the full license by clicking <A HREF="http://www.gnu.org/licenses/gpl.txt">here</A>.</P>
 
 <P>This license agreement is shown the first time the game is played. IT MUST NOT BE REMOVED UNDER ANY
 CIRCUMSTANCES. DO NOT DISTRIBUTE THIS GAME IN ANY FORM WHERE THE USER DOES NOT SEE THE LICENSE.</P>