So OP refers to these casinos as Altcoin Casinos based on the fact they accept alternative coins besides Bitcoin. Going by that logic, almost every Bitcoin Casino can be called an Altcoin Casino as well. Or an Ethereum/Litecoin Casino, etc.
To comment on harizen's list that he took from the site:
BetChain says in their opening sentence of their ANN that they are an
We are
www.BetChain.com, an
online Bitcoin Casino that provides you with a top quality gambling experience.
KingBit accepts Bitcoin and several altcoins. Technically, they can be considered both a Bitcoin and an Altcoin Casino. They have 'Bit' in their name so I al leaning more towards the 1st option.
It makes me wonder what the requirements are to call a casino a certain type?