Mike D's interview with me, about the Game Pencil Engine and more can be found at Nintendoenthusiast.com.
Here is one quote from the interview:
Nintendo Enthusiast: There’s a lot of middleware to choose from. Why go to the trouble of developing your own Wii U engine?
Nathan Hurde: Middleware tools are great, but I personally dislike many of the editors for them. Another thing I noticed was many middleware tools have a lot of overhead and MOST of the popular ones being closed source. The new Unreal Engine is, of course, open source, but it does not run on the Wii U (allegedly, at least). The Wii U has some great middleware tools already like Impact, Construct 2 and Unity but they all have their pros and cons. With our tool we aim to take the best traits of the middleware tools we know of and attach to it with more console-preferable optimizations and features.
You can read the rest of the interview at Nintendoenthusiast.com.