The "Plus-Size AT-AT" has the same playability and basic structure of LEGO's AT-AT sets, but with greater size, more detail, and a little more than 2x the parts (2493 in total).
It's intended to be a serviceable and hopefully well-proportioned "UCS" AT-AT for people who don't want to break the bank.
Thanks to Legolijntje for creating the .pdf instructions.
UPDATE (Dec. 19, 2016): Updated instructions now are available for download. If you downloaded the instructions prior to Dec. 19, 2016, I recommend downloading this newest version, which corrects a handful of minor issues. The parts list also has been updated.
As always, feel free to let us know if you have any issues with the model or have any questions.