How do you say "I already can tell (understand) X"?

Question

I want to say the equivalent of

I can already tell (understand) that game X is (going to be) harder than game Y.

For instance, I've already beat game Y. And even though I've only just started playing game X, I can already tell it is going to be harder than game Y. That's what I'm trying to convey in a sense.

I know that to say "game X is harder than game Y" you would say:

ゲームXのほうがゲームYより難しいです。

But I'm unsure how to add on "I already know/understand/can tell that.."

My best guess is something like:

ゲームXのほうがゲームYより難しいともうわかった。

But I'm not sure if that is right or if there is a better way to say it.

Answer 1

I don't really like xの方がyより in this order.
I would rather say it like

ゲームXはゲームYより難しいのはもうわかっている。

or

ゲームYよりゲームXの方が難しいのはもうわかっている。

Answer 2

for "can tell", as in I have the feeling that : the most natural would be "気がする"

ゲームXのほうがゲームYより難しい気がします

for "can tell", as in after thinking about it and i'm sure of it : "ことはわかる" as kiss-o-matic said would be right