Nice colourful stars in a lovely starfield, Salva.
How many frames did you take, and what was your exposure time?
Stars look quite round to my eye, so alignment/tracking is OK.
Do you think your focus is sharp? I'm not sure myself. How do you focus - do you use a mask?
Congrats on your first image here - better than my first several! (and come to think of it, probably better than anything I produce now

)