I am a career illustrator and I wanted to see if I had the chops for pixel art. I'm OK with attempt one but am happy to get CC if you got em.
Done on Libresprite Tab S6.
All made by the human brain.
Those unsmooth lines are also known as jaggies. Typically you can use a little bit of anti-aliasing to make it look smoother while also keeping the shape. I wouldn't say jaggies are completely off limits though, just generally undesirable, but I have in rare instances seen them used in ways that look okay.