What they got right: It's always interesting to see the Phantom taken out of the jungle environment. Using Sherwood Forest as the setting is interesting if only because there were no "Robin Hood" references. That's actually a point in the story's favor, since there's more to Sherwood, I'm sure, than Robin Hood and his Merry Men. The art is rather good, although different from the previous issues. The reasons for Teratos Birch's insanity sets him apart from other Phantom foes.
What they got wrong: Ultimately, though, it's a rather boring story. Gately doesn't write the story as if it came from the Phantom Chronicles, as his predecessors have. Instead, it's just a prose Phantom story, and surprising not an exciting one for the plot. Jungle animals somehow get involved, and are mostly explained, but still feel forced into the story. He can fight panthers in the jungles of Africa. This is the forest of England. Have him deal with a local threat; bears or wolves, or whatever they have in Sherwood. If Devil's origins (the current Phantom's pet wolf) was never explained in the strips, this might have been a good place to do so. If the origin HAS been done, then at least a nod to him would have been nice, but why fight animals from his homeland in a new setting, with plenty of other threats, including Birch himself?
Recommendation: Currently the weakest of the tales in this series. Mostly recommended for completists, but you're not missing much otherwise.