Five Bonus Lives
To earn five bonus lives, pause the game and push Right, Down, Right, Down, Left, Up, Left, Up, B, C, A and than Start.
Full powered up M.U.S.H.A.
To fully power up your M.U.S.H.A., pause the game and push B, B, C, B, B, C, Up, Down and then A.
Round Select
Wait for the SEGA logo to appear then press reset, repeat this 9 more times (for a total of 10 times). After the 10th time let the game go to the title screen, enter the Options menu while holding DOWN and LEFT on the control pad. You'll now be able to select rounds in the option mode.
Start with Twenty Options
To start with twenty options, pause the game then hit up, up, up, down, down, down, Left, Left, Left, Right, Right, Right, C, C, B, A and then Start.
Five Bonus Lives...