For the arcade, unlockables can only come in a few forms. Some give you ID cards to unlock stuff with your own profile. Taiko uses secret code sequences. They're sequences of the drum rim being hit in a certain order to unlock special features within the Taiko no Tatsujin arcade machines. New songs, Oni mode, and so on! Take these to heart if you do find a Taiko arcade machine in your area. This page also links to a few other interesting bits in arcade Taiko you might not find unless you dig deeper into the site, so it's for easy viewing. Enjoy!
As for the consoles, the methods to unlock stuff vary widely between each game. You can either see them here or, if we've already written it, on the individual game's page.
Oni difficulty -----
Ura Oni difficultySoroban 2000 Morse Code
Arcade
(Taiko 7-14) Gameplay modifiers
(Taiko 7-14) Taiko Dojo
(Taiko 10-14) Song order
(Taiko 11-14) Taiko sounds
(Taiko 12.5, 13) Song unlocks without secret codes
(Taiko 14, 0) Shin-uchi Mode
Song unlock codes
Taiko no Tatsujin 10
-Code 1
Taiko no Tatsujin 11 / 11 Asia
-Code 1
-Code 2
Taiko no Tatsujin 12
-Code 1
Taiko no Tatsujin 12 Asia
-Code 1
Taiko no Tatsujin 12.5
-Code 1
-Code 2
-Code 3
-Code 4
-Code 5
Taiko no Tatsujin 13
-Code 1
-Code 2
-Code 3
-Code 4?
Taiko no Tatsujin 14
-Code 1
-Code 2
-Code 3
-Code 4
-Code 5
-Code 6
-Code 7
Arcade (Taiko no Tatsujin HD)
(under construction)
Gameplay modifiers, Taiko sounds
Costumes
Opening/closing song folders
Console
Taiko sounds
Gameplay modifiers
Don Point ranks
Don Point cheat
Costumes
-Taiko DS1
-Taiko DS2
-Taiko DS3
-Taiko Wii 1
-Taiko Wii 2
-Taiko PSP DX
-Taiko Wii 4
-Taiko 3DS
