I'm not one to hang out in lounges and bars but this little place is more like sitting in a giant aquarium. It's a decent place to grab a comfy seat and watch the fish swim back and forth. There's a cool-ish vibe to this lounge. It's dark and has a great view of the beautiful aquarium.
The bar snacks here are good, I love when they have the deep fried Twinkies (yeah, I said it) on the menu. The bad things about Mermaid Lounge is that it is SUPER SMOKY (as with most places located right smack dab in the middle of the casino) and it can get very loud. Not really worth a special trip to go here but if you love fish and aquariums, you'll get a kick out of sipping your house wine at this bar.