If you don't have a high end PC , leave this game in the stores.
You could ask yourself, is it really honest to give a game a lower grade then it should have just because high end system requirements? Usually i would say no but i think this game could be lots faster then it is now, Because the graphics are not superior and with a little tweaking it should run a lot faster, well im no game-designer but im sure they could have fixed it.
Besides the system requirements, the game itsself seems pretty nicely done , i do not own the full game but i surely will recommend this game to people with a high end pc (damn how many times i wrote that word?:P)