its a swamp/forest campaign, so lots of the flooded sugar mill style gameplay, with a set piece on all the stages which work well, and a pretty cool final piece similar in style to the no mercy finale.
i'd say its definitely worth checkin out, although i would advise playin it with others instead of the AI (i used the AI and instantly regretted it when i remembered they insist on melee'ing whatever it is that grabs/pounces/face-humps you instead of using their RANGED weapons like sane people

http://www.l4dmaps.com/details.php?file=4634
incase people havent installed community maps before, just unzip the download and then copy the file that extracts into the following folder (obviously exchange drive letters and Steams install location to ur own setup =D )
(C:\Games)(change as needed) "\Steam\steamapps\common\left 4 dead 2\left4dead2\addons"
and thats it, file installed, now when running L4D 2 start 'campaign' then 'add-on' and select the map.
sorry for the long post, hope it helps and if ppl like it maybe we can chuck it into a social LL rotation before the april =)