Ignore the marbles and just collect bullets to fire at him. Make sure though you keep his marble level at zero or close to it at ALL times. Doing this will allow you to get your marble level up to approximately 85 within a few minutes.
Outside the entrance to 'Hungry Tonight?' collect the Power Parp Tin from Snott and use it to collect the nearby extra life. Then enter 'Hungry Tonight?' and immediately exit. Talk to Snott again to get another Power Parp Tin and collect another extra life, keep repeating this process to get as many extra lives as you want.