Happy new year sir,
That might happen indeed, is there some sort of anti-aliasing option for the conversions? The tail of this model is a great example if you ask me where anti-aliasing fails.

Hi Rikkert,
... and a happy new year to you!
Thank you very much for your feedback. I will try to incorporate it next time and see, whether the results improve. I do think the problems arise from the .png conversions, as the original files are vector-based.

I really like your work, the best on the workshop atm, however(and I am going to be honest) I think the edges on the plane are too 'jagged' (Google it if you dont know what it means)
I think you can improve this by drawing your lines of the plane with anti aliasing enabled, also try to do 'supersampling'. Make a 4 times larger sprite (instead of 854x834 for example 3416x3336 and then scale down)