I think maybe it’s a bit more structured. Delivered as written it seems a bit disjointed, even for free verse. The theme is great though and there is a pretty prevalent rhyme pattern which would be obvious if we re arranged some things.

The one who kills
is a demon in you
you have no soul
nothing that makes you, you.

You're nothing but a killer
inside your head.
I can't wait
till your demon
is finally dead.

So let's go off
to the killing field
I'll make you hurt,
I'll make you feel.

Let's make this a game
just you and me
you go hide,
I'll count 1,2,3
ready or not
here I come
hide really good ‘cause this game
has finally just begun.

Who will win
let's make it a tie
either one or both
can surely die.

This game we play
will never end
‘til we're buried and
dust again.

I would play around with the last four lines of stanza 4. A quick lesson on colloquialism in writing. So I’m into folk writing quite a bit and because is never fully pronounced. In writing we show the reader these common speech variations with apostrophes.

because_’cause or ‘cuz
until _’til

Those I’ve corrected. In my re arrangement.

I’ve been following your work closely. I like your style and subject matter choices. I think you have nice complete thoughts on the page. My only critique would be format and some grammatical baloney which is more formality. I hope I haven’t over stepped.

Excellent
Tim