If you have some knowledge in coding you can with ease switch some grafical parts and then just alter the .css for them.
I based it on subSilver (ofcourse) and the stripped away all unnecessary coding.
Then I altered the tables to a :
skeleton and some other stuff. But overall, it's really "clean" and easy to alter if you have the very basics of handleing html/css.
Ill have it done by saturday/sunday
But if you plan to alter it then you have to release your theme somewhere and give me the link. There are WAY to few nice game templates out there for phpbb.