As gameplay, the chickens are disappointing. It is a set of “go talk to x” quests, with poor directions to x. Despite being just outside the hobbit starting area, this is not newbie content. You must know where things are and be able to find them with a blank map while playing a level one character. Taking a chicken through the higher level areas is presumably an interesting challenge, although having a babysitter makes it much easier. The greatest annoyance is uninteresting running. If your quest is “talk to animals in Bree,” your first step is a five-minute run across the Shire to Bree, an almost perfectly safe run with just enough twists to keep you from going AFK with autorun on. Bottom line: not fun once the novelty of “lol chicken” wears off.
As a story, it is without value as far as I have seen. Chickens are scared, you talk to other animals, they say they will not help. Every time. As a tech demo, I suppose it is okay. There must be some technical issues in moving from a PC to a connected one-shot puppet. It is a shame that everything is flushed between sessions, including your map. Building up a chicken could be amusing.
In many ways, chicken play is the logical extreme of The Lord of the Rings Online™: Shadows of Angmar™. If you read The Lord of the Rings and thought, “I wish I could be a secondary character doing sidequests while Frodo carries The One Ring,” The Lord of the Rings Online™: Shadows of Angmar™ is designed for you. Taking it one step further, what if you were a hobbit in The Shire, and you could level by delivering mail or gathering eggs? Taking it one step further, what if you were a chicken in The Shire, laying those eggs? Just $15/month, baby!
I have not tried a troll or ranger in session play. From what I hear in /ooc as a monster, the freeps use rangers as mobile artillery platforms at the center of groups, while the creeps avoid using the trolls for fear that the human players will give up and leave. Your server may vary.