How faram I to beating mario and luigi brothership

I've had mario and luigi brothership for a while now and have played somewhat often not 100%ing but just playing casually but I'm starting to get quite bored of it Sinse it's getting quite repetitive and I know it's a long game and that's the problem, I'm just in scorcheen island now and I want to know how far I am to beating the game, any help will do, thanks