I had a recent go at astro photography myself (
coupled to a landscape).
I had a hint of star trials at 20s with a 24mm lens at full size. I would describe yours as
having obvious trails at full size (albeit short ones). They also wiggle. Was this taken using a tripod?
Next time, don't be afraid of high iso and shorten your exposure time. Noise is not really
a concern for pure sky shots as you have no shadows, just pitch black sky. So you can
easily control the noise as you seem to have done with the +2 exposure (also relatively harmless).
Fun stuff to play with. Keep working on it.