ECs are a very important part of your application. They help you highlight your interests and the way you mobilize your efforts towards those interests. If you've had significant achievement across any of those activities, that's a bonus. Significant here would mean bagging awards at State, national or international levels. That puts you at an added advantage besides stellar academics and sets you apart from the rest of the applicants. While applying to the USA, HK or Europe, keep in mind that the universities are looking for a reason to select you and that would be decided by what sets you apart from the rest of the cohort (hence highlighting why diversity is an important factor in the admissions process).
You don't really need to do something out of the world; but achieving something distinctive even in something really simple can mean a lot to the admissions committee. Also, do not forget to include your explanation about how your extra curricular activities set you apart in your essays, provided you find the space to! (Don't just squeeze it in and make the essay go off topic).
P.S - maybe rubrik cubes can help the admission committee gauge your analytical and problem solving skills in a creative manner? You just need to show this in your essays if asked! or in some other blank space where you could put something extra in:)
Good luck with your applications!