Yes, I thought your line based vector graphics were fine however I didn't think the "glow" effect around the lines were particular suited to the super low resolution you chose.
To get an idea of some very nice retro style graphics, which I think suits your style, see these games here:
- https://spectrumcomputing.co.uk/index.php?cat=96&id=17728
- https://spectrumcomputing.co.uk/index.php?cat=96&id=6959
- https://spectrumcomputing.co.uk/index.php?cat=96&id=10729
- https://spectrumcomputing.co.uk/index.php?cat=96&id=6538
If you are doing line based graphics, 256 x 80 resolution is a good choice, and choose a limited palette. There are lots of cool palettes to choose from here:
https://lospec.com/palette-list
Leave off any effects (like glow) that would lower the effective resolution further.
Teletext graphics may be something that you want to experiment with, but I understand that this is THE most difficult type of art because it's so hard to fit a lot of concepts into a tiny amount of pixels.