Here is a patch that will convert Arkanoid's mapper from CNROM to MMC3.
7/31/13
infidelity
Converting Arkanoid From CNROM to MMC3
MMC3 Register Setup Reset Vector
$65 = 4CB0FF
$7FC0 = A900 8D0080 8D0180 8D00A0 8D01A0 8D00C0 8D01C0 8D00E0 A205 8E0180 BDD8FF 8D0180 CA 10F4 4C6580 00 02 04 05 06 07
DONE! Arkanoid is now MMC3! :-D
-infidelity
Arkanoid (USA).nes - NOINTRO
CRC32: EE93A28C
MD5: 6A2BFA3C6E9B1CE1E21AABD0DFBF2779
SHA-1: B2B30C4F30DD853C215C17B0C67CFE63D61A3062
SHA-256: 93A46EF4B06AE30682D3CC19CE4B77DA7F98F0DDAF9A3280325A347B5CBBF811