you can expect to murder.... a lot.
you can expect to use special moves... a lot.
you can expect to use a combination of two buttons... a lot.
you can expect rock versions of a number of zelda songs
tons of nods to the series causing the game to not feel like something made with zelda in mind, but something lovingly crafted from hardcore zelda fans.
As for replay value it will depend if you want to do everything... if all you want to do is burn through the story you likely won't have much reason to go back to the story... now if you want to collect rewards and get more and more power then there is a ton of replay value, with people clocking in over 100s of hours already.
not only is there a hard mode, there is a really hard mode that you won't be able to complete until you gain way way WAY more power then you needed to beat the game on hard.
there is also that, as the OP is amazing and keeps updating. My condition of reading the OP once and never reading it again unless I need certain info I know was there makes me forget it often