A recent Japanese field test by Niantic, the company behind Ingress and the highly anticipated Pokémon GO, allowed a lucky few in Japan to try out the mobile game for the first time. Some of those users decided to share the fun with the rest of us. A Reddit post on /r/pokemongo and another on /r/TheSilphRoad compiled all the information found so far, including some screenshots and code from the games files, revealing an enormous amount of information not yet released by Niantic. This includes the Pokémon available currently, movesets, biomes, items, information related to eggs and evolution, and other potential variables. This is all in very early beta stages so obviously this information may not be complete and Niantic may still introduce new content before the full release. For now this is a small taste of what to expect from augmented-reality title Pokémon fans have been waiting for.
Some screenshots were posted, however few remain after Niantic requested some be taken down. Most include a watermark which includes user information causing users who share the screenshots to be swiftly banned. However there are some copies still floating around showing what some of the games menus and the opening screen might look like. (There is also a purported video of the game however it has been removed from YouTube and the only available mirror is not available due to the sheer number of users trying to access it).
The most interesting content though is that which was found in the code itself. Between all the diggers nearly everything currently in the game is now revealed except multiplayer aspects. Players pointed out that the game seems to be a whole new creation (alleviating fears that Niantic might recycle assets or code from their already popular mobile game Ingress, which uses similar concepts to the future Pokémon title). Among the code was a list of every Pokémon trainers can discover in the game. Currently, the list includes only the original 151 - which will be a delight to some (and obviously, Niantic may release updates to introduce more in the future). There is also a list of moves the Pokémon will be able to learn, codes for how gym badges will be earned, seven new natures Pokémon may have (Stoic, Assassin, Guardian, Raider, Protector, Sentry, and Champion), potential feedback that offers clues to the types of activities that will be included, and clues about how locations, day and night, and other factors are accounted for. The data also reveals some information about the in-app purchases that will be available (don't act surprised). 
In the code, the Pokémon you encounter in Pokémon GO are called "HoloPokemon". As previews have already shown you "catch" these Pokémon by walking around in real life and pointing your phone at the empty air in front of you until a wild Pokémon emerges. What these previews don't showcase fully are how you can join different teams which battle each other to defend gyms, collect gems in order to evolve your Pokémon (they don't seem to evolve in the typical way), and that there are icons and labels for different "biomes" which could possibly be reliant on the actual environment you're in.
There is also information in the beta code linking it to Google Cardboard, the company's answer to virtual reality headsets. Some other bits of code reveal that there is definitely something regarding the PokéNav from Hoenn region games (Ruby/Sapphire/Emerald and the remakes) though what purpose it serves isn't clear.
More information will likely be revealed soon, and potentially more by the testers and Niantic themselves. Shortly after announcing the field test, Niantic released some of their own screenshots on their blog, and some additional information about the overall structure of the game. Still no word on the games actual release date, but based on the scale of this beta, it may be sooner than expected.
