See It For What it Is
From the beginning when this game was first revealed it was made known it was a hack and slash.
It is a spin off from the standard MGS line, it's not fair to slate it because it is not the game you wanted it to be.
If you don't want a game like this then wait for MGS 5 which has been announced.
This is Metal Gear Rising not Metal Gear Solid, different games!
It's the chance to experience the MG world from a different view point. Metal Gear has always been over the top and this keeps up that wacky traditon.
Definetly worth a try if you are an MG fan or just enjoy a good fighting game.