If your design is only design issues (css and stuff) and no/minimal code changing, I would compare your visitor stats, new visitors & retention of new visitors; run with the new design for a bit.
I think that a decision to change the design is very much up to you and the group of people that are running the site. On the one hand: If it ain't broke, don't go fixing it; On the other hand: Gaming sites need to be somewhat forefront site I think. Gamers typically would be into computers, web and digital stuff, and expect flashy, trendy sites.
Personally I'd prefer the newer design.