You have the main missions and side missions without forgetting that if you recover plans you can create new weapons (baseball bat with nails devastating effect).
Sure there are bugs but the life of the game is long and the exploration side of the island is vast: one can rummage around (suitcase, dead zombies, garbage cans etc), there is also possibility of use 4x4 (nice against the zombies).
At times, one can opt for the side "nag" but I advise caution aside and play with the water because the zombies are not sure swim so if you put a kick a zombie and you are in water .... look at the result.
Graphically, the rendering is beautiful, the dialogues are in English subtitled in French.
I highly recommend it.
