The following are known Action Replay Codes for Rhythm Heaven on Nintendo DS (NDS).

Game ID: YLZE-77E87D15

PROFILE 1: UNLOCK STAGE CODES:

All Stages Unlocked (Press Select)
94000130 fffb0000
222a4f3f 00000002
d5000000 00000002
c0000000 00000019
d8000000 022a4f24
d2000000 00000000
94000130 fffb0000
d5000000 00000002
c0000000 00000018
d8000000 022a4f42
d2000000 00000000

All Stages Unlocked + Complete (Press Select)
94000130 fffb0000
222a4f3f 00000002
d5000000 00000003
c0000000 00000019
d8000000 022a4f24
d2000000 00000000
94000130 fffb0000
d5000000 00000003
c0000000 00000018
d8000000 022a4f42
d2000000 00000000

All Stages Unlocked + Gold Medals (Press Select)
94000130 fffb0000
222a4f3f 00000002
d5000000 00000004
c0000000 00000019
d8000000 022a4f24
d2000000 00000000
94000130 fffb0000
d5000000 00000004
c0000000 00000018
d8000000 022a4f42
d2000000 00000000

All Stages Unlocked + Perfect Medals (Press Select)
94000130 fffb0000
222a4f3f 00000002
d5000000 00000005
c0000000 00000019
d8000000 022a4f24
d2000000 00000000
94000130 fffb0000
d5000000 00000005
c0000000 00000018
d8000000 022a4f42
d2000000 00000000

PROFILE 1: UNLOCK EXTRAS CODES:

Unlock Cafe
222a4f40 00000001

Unlock Medal Corner
222a4f3e 00000001

Unlock Battle of the Bands
222a4f41 00000001