That stuff is definitely strong! There are places selling these frozen drinks all along the strip, but Fat Tuesday is the real deal. The other places have fewer flavors and mostly the "traditional" stuff (e.g., pina colada, strawberry daquiri), and their slushies don't have alcohol added in. They will put in maybe 2 shots and then you have to pay more for extra shots.
This isn't the case at Fat Tuesday. Their slushies actually have alcohol mixed in. And plenty of it. They have a lot more flavors, all with interesting names. And then in addition to that, you can get an extra test tube shot (for a little bit more $). I personally wouldn't get the extra shot because they use an inverted test tube, so it really doesn't mix in that well, until you get to the very end, then all of the alcohol in the test tube comes out and you're basically drinking straight liquor...