It's conveniently located in the walkway of shops between MGM and the MGM Signature. Their alcoholic slushies are great. I found them to be less sweet than the famous Fat Tuesday ones but just a strong. I tend to avoid Fat Tuesday drinks because they are way too sweet. They also make their slushies strong with everclear, and have the option to purchase an additional shot.
PROTIP: They offer refillable cups so if you are staying at the MGM this could offer a better value.