Hello summer09,
Yes, you can go to the Atlantis for free, but don't count on getting anything there for free or even cheap! The prices are outrageous (try 10 - 12 bucks for a beer, nevermind a mixed drink). It is a gorgeous place, however. My then girlfriend (wife now) and I went there in October 2006 on the Valor. We rented a moped and rode over the bridge to the resort. Mopeds are cool, just be careful as you ride on the left and the locals can be a bit crazy.
Enjoy!