To activate the cheat codes you need to go to the Main Menu -> Options -> Enter New Cheat, then enter the following combinations. If you press the keys correctly, you will see a message on the screen.

Cheat Codes:

All HOPOs

Twice Green, Blue, Three times Green, Yellow, Green

Focus Mode

Yellow, Green, Red, Green, Yellow, Blue, Twice Green

Performance Mode

Twice Yellow, Blue, Red, Blue, Green, Twice Red

HUD Free Mode

Green, Red, Twice Green, Yellow, Three Times Green

Unlock all characters

Twice Blue, Twice Green, Red, Green, Red, Yellow

Always Slide

Twice Green, Twice Red, Yellow, Blue, Yellow, Blue

Auto Kick

Yellow, Green, Red, Four times Blue, Red

Invisible Characters

Green, Red, Three times Yellow, Twice Blue, Green

Air Instruments

Twice Red, Blue, Yellow, Three Times Green, Yellow

Contest Winner 1

Twice Green, Twice Red, Yellow, Red, Yellow, Blue

Tips:

The Always Slide mode turns the guitar notes into touch pad sliding notes. The sliding notes are connected by purple lines, but it has absolutely no effect when playing online. Unfortunately, when playing with this mode you can earn no achievements.

The Auto Kick mode also has no effect when playing online. It plays the bass pedal for the drummer automatically and you can also earn no achievements with this cheat code.