Brave Tank Hero previously came to the North American 3DS eShop on August 11. Later this week, Wii U will be receiving the game as well. Natsume confirmed on Twitter today that the Wii U release is slated for August 27.
It's time for some action! Brave Tank Hero arrives on the North American Wii U eShop starting August 27th~ pic.twitter.com/XwbeGLZABB
— Natsume Inc. (@Natsume_Inc) August 24, 2015
Thanks to Jake for the tip.
Update: Bumped to the top. GameStop’s Canadian equivalent, EB Games, will be giving out its own double-sided poster with pre-orders – see below (thanks Zach!):

GameStop is offering a bonus with pre-orders of Animal Crossing: Happy Home Designer. By reserving the game, you’ll be given a unique poster.
Pre-orders can be placed online here. The offer is valid in-store as well.