I went a few years ago when i visited my daughter who spent the summer in Europe. As far as shoes, I think it depends on what part of the day you go and if you would like to gamble a little. If you go at night, you will likely need a pair of nice shoes and a jacket. If you go in the early afternoon, then you may be able to get away with nicer looking tennis shoes (black on black so they aren't too obvious like white tennis shoes).

A couple of things to note when I went:

> Casino gaming is not open 24 hours, it opens around Noon (i think) and goes to early morning). Check website for hours.
> There are tours available in the morning, but you need to buy tickets. Not really a tour, but you can walk around pretty much the entire casino. Check website for hours. Also, can't recall what time the first tour was. I don't think there is a dress code for the tour. Also, they said no photos but i snuck a few in.
> If you would like play at a table, you need a players card, which you can get before hand at the Casino Cafe' de Paris, which is right next door. Also, i don't think this place has a dress code. From I can recall its all slots. See pic of entrance below.

I went to the tour in the morning, went to eat lunch and came back and sat at a black jack table for a little bit. I wore my black on black tennis shoes, some nice long pants (nicer khakis) and a short sleeve button up collar shirt. No one stopped me at all. When it opened, i think only 3 or 4 tables where open. I played like for an hour or so then had to go. Besides, I didn't bring enough Euros on my vacation to gamble with lol.

Hope you have a great trip!