So I have recently just started game developing. It’s an 8 bit game with a mixture of mega man, Mario, and metal slug mechanics. Its meant to be a nes style game with an “impactful” storyline. I am proud of my progression I’ve figured out most of what I wanted under a week (which is impressive compared to everything else I’ve done) and so I’ve been communicating to my siblings my dreams for the game, most have not cared (which I’m okay with.) and others have just said to keep going. But one sibling(Overwatch player) has given criticism which I would be fine with if it wasn’t the fact that i feel he is feature creeping. He goes on about adding character customization, multi character leveling systems and a slew of mechanics that I don’t feel fit what I wanted to do in the first place and feels very discouraging (keep in mind this would be my first game) The Question is should I listen to these suggestions or finish the game with the intended idea?
When it comes to criticism and feedback, it’s kind of like taking in other information and you have to consider other factors as well. Don’t try to please everyone - it’s impossible. There will always be someone who wants to raise the bar higher and higher, and refuses to be pleased. Trying to meet their expectations is going to just drain your creative energy in the long run, not to mention being very stressful.
Use what would be an improvement if it is aligned with your vision and fits well into the type of game you’re creating. If not, into the bin it goes. This sibling surely isn’t going to be your only player, so you can’t worry about tailoring your game to suit that one person.
If hundreds of people start playing and it becomes a “popular demand” thing, then maybe you can reconsider or even create a different game for that audience when you’ve finished the one you really want to do.
Thank you for this advice. It’s definitely a philosophy I should follow. I appreciate the response!
You’re welcome 
I hope the stress is less!
Having worked in IT for may years, freeping ceaturism was an issue that always had to be dealt with. Do we give the user that one more feature by either extending the delivery date or burning out the programmers; or do we deliver what they first asked for then follow up with an update (this is one of the big advantages to using the Agile development method - the choice becomes theirs not the development team’s). Duke Nukem 3D is an excellent example of what happens when you get into the “just one more feature” loop - it was delayed, rewritten, rewritten again with a new engine, made faster, new graphics and finally crashed and burned. They started development in 1997, crashed and burned in 2009 (12 years of wasted effort), then in 2010, was taken over by another company and published (to mixed reviews) as Duke Nukem Forever.
Stick by your original plan and make note of those enhancements. Once it is out in the wild, and frequency of reported bugs as leveled out, then start revising it to add new features (maybe as an in app purchase?).
Good luck!