That's really good advice actually, thanks for pointing that out. I see that I will, to a point, always be better than a new player since I'm familiar with the game while they're not. I see that having to make some levels more forgiving, and reducing the spike hitboxes will make the game feel more fair.
I'll keep your advice in my head while designing other platforming-related games! Hopefully you were at least able to have some fun though :3