If you want see the effect of HN on a new repository: https://star-history.com/#samwillis/tetra&Date

It was on the HN homepage for about 5 hours yesterday, never higher than about 25. The initial jump on the 25th was some attention on Twitter. Also the HN link was to the website, not the GitHub. I imagine if it had been a link to the repository the stars would be higher.