Pros:

Nice map design, lots of choices
Loved the long grass in map 2
Nice landscape in map 2.
Enjoyed the finale.

Cons:

Lack of meele weapons
Lack of health kits + ammo throughout the map 
Far too dark!
Pointless emergency door before entering sewer, can just jump over tent (1st map)
Seemed quite repetitive a lot of the time, in and out of sewers.
Quite buggy in swamps, friend got stuck in a tree and couldn't come down. (3rd map)

Conclusion:

Just fix a few of the bugs and turn the lights on and you have a great campaign that could be really enjoyable.
Good job.