Adventures in Middle Earth

5E Tolkien
White Box seems influenced by the fantasy work of J.R.R. Tolkien despite Mr. Gygax's supposed dislike for Middle Earth. Hobbits, Ents, Balrogs, straight out of Middle Earth appear in early printings of White Box. According to gamer legend, the Tolkien estate lawyers thought White Box was infringing and forced the removal of those names, but the Middle Earth beings remained in the game with slightly changed names. Mr. Gygax was a fan of R.E. Howard's Conan from boyhood (according to biographer Michael Witwer) and his game may lend itself more to a play style similar to Howard and other favorite authors than Tolkien in many ways. Making White Box or the later Editions feel like Middle Earth has always been a challenge.
Cubicle 7 has had a pretty faithful Middle Earth game out for some time now titled The One Ring (TOR). It is more of a story-telling game than The World's Most Famous RPG, but seems to capture the flavor and feel of Tolkien quite well. The folks at Cubicle 7 have released a digital version of Adventures in Middle Earth, a player's sourcebook for gaming 5E (using the OGL) in Tolkien's Third Age. I have not played AiME, but have read the Players Guide and will share some of my thoughts about the book and how 5E can be adapted to a specific setting quite different from it's implied default (The Realms).
Adventures in Middle Earth (AiME) replaces the traditional game races with a classification termed cultures. Dwarves, hobbits and elves each have a culture and humans have several from which to choose. Each culture is associated with a virtue - virtues are either open and anyone can take them or cultural and limited. Virtues function similar to 5E feats except they are exclusive to some PCs. This is one way AiME maintains variety and niche protection.
The standard classes are replaced in AiME with Scholar, Slayer, Treasure Hunter, Wanderer, Warden and Warrior. Note: there are no 5E style spellcasters. The classes each have subclasses and give a nice mix of abilities and skill sets. Some classes have special abilities that trigger off Inspiration and not all classes are competent at combat. AiME is a campaign setting/game that balances combat with other challenges so all the classes contribute. Each class has a shadow weakness which can lead to corruption.
AiME presents the PCs with several Middle Earth backgrounds and I think this helps meld 5E to the setting. New traits include Hope and Despair which are carry-overs from TOR and seem full of Tolkien flavor. The alignment system is dropped and replaced with corruption. Shadow weakness, which is tied to class, can lead to madness and degeneration as can exposure to, or contact with, shadow forces. Simply fighting the bad guys can lead PCs into shadow effects making for a dangerous world.
Weapons, armor and equipment are customized to give a more Dark Ages/ Middle Earth flavor and the addition of a few new skills associated with the literature helps this felling along. AiME is about more than killing monsters and taking their stuff. Journeys play a large part in the fiction of J.R.R. Tolkien and journeying is significant in AiME. During the journey phase of play each PC assumes a task such as guide, scout, hunter or lookout. AiME includes additional rules for perils, challenges, encounters, events and arrivals that make the journey feel like an important aspect of play (something like in the RPG Ryuutama). At the end of a journey players may have arrived at the residence of an important person and seek an Audience. The Audiences are an important part of AiME as forming relationships plays a significant part in the campaign. Rules for the Audience involve cultural attitudes and skills which favor some PCs who might be weaker in combat. It also allows for player to meet the movers and shakers (favorite characters from the fiction) of Middle Earth and do some role-playing.
The Fellowship Phase (again borrowed from The One Ring) covers rest and recovery from injuries and corruption and whatever else PCs do when not adventuring on the road. The time may be spent training, to gain a new talent, to meet a patron, to open a sanctuary, receive a title, or research lore.
At the time of this post only the Players Guide for AiME is available and it does not include any monsters or much information on the setting of Middle Earth. A Loremasters Guide is promised and will presumably cover the rest of the game rules and setting information. As it stands I believe AiME's Player Guide illustrates many of the aspects of customizing 5E for a specific setting and highlights 5E's ability to be modified for a setting quite different from The Realms.