The download link for the practice rom can be found here.
Note: To install this on a Wii U, you are going to need a homebrewed console which can be done by following this guide.
First, you are going to need sdcafiine, which can be downloaded here.
Once you have that downloaded, extract the downloaded zip to the root of your SD Card
Once there, go into the sdcafiine folder and replace YOUR ID HERE with one of the following IDs:
NSMBU (JP) 0005000010101C00
NSMBU (US) 0005000010101D00
NSMBU (EUR) 0005000010101E00
NSMBU+NSLU (US) 000500001014B700
NSMBU+NSLU (EUR) 000500001014B800
To use, simply boot up SDCafiine, and then boot up your copy of NSMBU
From there, all you have to do is load the level you want to practice, and then use any pipes or other features the level has.
This is a first of it's kind, meaning all these are new and exclusive to this hack! This includes:
Pipes to reload or warp to sections you want to practice
Power up blocks placed in places so you can get back lost powerups
Red pipes indicates boss warps
Extended time on every level
You will need a hacked Wii U and FTPIIU Everywhere
Note: This works on both the physical and digital version of NSMBU (Physical untested)
Backup anything such as save data, update data, DLC, or anything else you want before you do this.
Go into system settings, data management, Copy/Move/Delete data, then System Memory/USB Storage device depending on where the game is stored at.
Delete everything in the NSBU title except the game itself (Update Data, Save Data, and DLC).
After this is done, go to the homebrew channel.
Open FTPIIU Everywhere, and you will see an IP Address and a port.
Open a FTP Client on your computer (I Prefer FileZilla).
After FileZilla is open, under Host put your Wii U IP, and in port, put your Wii U's port, then leave the other fields blank and click Quickconnect.
You then need to navigate to storage_slc/security/versions.bin
Note: You should backup this versions.bin file. It essentially contains your Wiiu's memory of the updates. Losing this might be bad for other games so you should back it up on your computer. You can also hex edit just the NSMBU part, but this hard and makes booting the game more inconvenient, so I recommend against it.
After you have found versions.bin, you should copy it to somewhere on your computer, and then delete the one that is currently there on your console. After this is done, you should be able to boot up NSMBU on Version 1.0!
This hack was made by me (Saria_100), and Astix gave feedback and helped make the elevator level