Did you reverse-engineer the original Flappy Bird to get the feeling so similar or just experimented until it felt right? What I don't like is that you ripped

Did you reverse-engineer the original Flappy Bird to get the feeling so similar or just experimented until it felt right? What I don't like is that you ripped off everything 1:1 without giving credit. Yes, right now, everybody knows Flappy Bird, but in a year, it'll be forgotten. Just for the sake of proper archiving, you should mention where the graphics and everything else come from.