Is it illegal to directly embed browser games in your website?

Is it illegal to directly embed browser games in your website?

So I am making a browser game website in Google sites as just a little side project but what I'm doing is that I'm directly embedding it into the website for ex - I am like copying let's say this game called deadshot.io so I search deadshot.io and then I directly embed it into the website, But is it illegal because I have seen different types of these sites some uses crazygames embed feature some use it with others company embed feature with ads so why are these websites not doing the same thing as I am, is it illegal and will I get sued if try to publish it online.