Single player is amazing, good story and good full on fighting/action.
Player Vs Player probably one of the worse PVP games out there,
Horder mode is brilliant but addictive
another big flaw is if you want to just play for 10 - 20min then thats out of the question as you have to play what seems forever.
Don't buy this game if you just want to play PvP its an awful experience.
Single player + Horde are brilliant though.