Yeah but to my understanding, slot games are not their own games, they just host them. Plinko, Dice, Coin Flip, and the one with the rocket raccoon (I forget the name), are their games. In a sense, because there are variations of these games on similar websites. You can play those with the faucet money.
Naturally they are not their games, it takes time and money to devolope those, (and usually designers have to pay royalties for copyrights too), And you can even filter them by the developer. But does that really matter if we can use them to mine BFG tokens anyway?