It's been six months since Mighty No. 9's launch and there's still no sign of the remaining physical backer rewards. The art book, NES/Famicom cartridge USB drives, printed game manuals and signed sketches remain missing in action. Sadly, Comcept haven't said a word on the issue - not a peep. You can e-mail them, you can tweet them, you can shout from the rooftops... and you'll still get nothing.
Fortunately someone has stepped up the the plate. The merchandising company contracted to produce the physical rewards, Fangamer, sent the following message to fans...
"Hey folks, this is Steve from Fangamer. We’ve been receiving a lot of questions from Mighty No. 9 backers regarding their remaining physical rewards, and I figured I would chime in here to clarify what’s going on from our end.
We (Fangamer) were contracted by Comcept to produce and fulfill the physical rewards (up to the $250 tier) for their Kickstarter project, however this is contingent on Comcept providing us with the necessary assets we need for fulfillment.
The question we’ve been receiving the most has been “When will you begin shipping the rewards?”. The remaining physical rewards are currently in production, and while we can provide estimates based on our (Fangamer’s) internal time-frames (e.g. Early-2017), these estimates are based on the assumption that we will receive all required assets from Comcept, and unfortunately we currently do not know when they will give them to us. Therefore, until we receive everything we need from Comcept, we cannot give a specific shipping time-frame just yet.
Also please keep in mind that our involvement in this project is limited to merch production and fulfillment for Comcept. While we’re happy to answer questions sent to our firstname.lastname@example.org customer support email address, we are not involved with providing updates or PR for this project; that is Comcept’s responsibility.
The Mighty No. 9 shirts, plushies, and boss posters were shipped off in 2015. If you were eligible for but haven’t received these items, please contact email@example.com for support."
tl;dr the rewards are still coming but Fangamer are waiting for Comcept to deliver the assets needed to actually produce said rewards. Fangamer *hope* to ship everything out early this year, but that is entirely dependent on Comcept's diligence (or lack thereof).
So hang in there, backers. I'm afraid there's very little we can do other than wait.
Source: GoNintendo via NeoGAF (thanks, GodDamnProtoman!)