Automatic rotation of pixel art by other angles than 90° usually goes wrong. If you want to maintain the pixel-art aesthetics you usually won't get around redrawing your art in each angle.

If you use a faux-retro look where your sprites are actually in a far higher resolution than they look, you can sometimes get away with upscaling them by an integer factor without interpolation in your graphic editor and then rotating them in *linear* interpolation at runtime. To avoid your sprites from getting blurred while in original orientation, always ensure that the drawing position is rounded to the nearest integer. But that's usually still just a lazy substitute which doesn't reach the quality you can reach with manual work.

Here is an example of a sprite in the original size, upscaled by factor 3 without interpolation and then rotated by 30° with linear interpolation:

[![enter image description here][1]][1]


 [1]: https://i.sstatic.net/cICjf.png