I dont get the secrecy on a question like that. You do need the dev kit to test the game on Wii U hardware. A retail console wont work.
There isn't any reason for the answer to this question to be considered behind the NOA NDA. There's no connection whatsoever, and the information has been posted publicly by Nintendo.
So, to answer the original question by bpetersen, Nintendo has a couple of options (posted publicly) for Wii U development kits. There's two models, and the less expensive model can be used for C2 development - the other one is geared more towards Unity or full-fledged 3D game development. The only way to reliably test games is on the development hardware Nintendo provides. They previously offered a leasing program for the development kits, though I'm not sure they still do (and that information is no longer posted publicly), but in all honesty, I wouldn't bother - the NX will be out in less than a year and seems like it will be far more capable in terms of what's possible with C2 on Nintendo platforms. The state of C2 development on Wii U is poor, though this is not the fault of Scirra or C2 (the exact reasons why are, sadly, behind NDA).
There's information related to using the Nintendo Web Framework (also public) in this Reddit thread that may be of use:
And just to be safe, in case the info is covered by Scirra's NDA (it's not covered by mine, but the info is no longer public on Nintendo's developer site), if you just search for "Wii U Dev Kits" you can get more information on the differences between Wii U dev kit models.