Need your opinion about underpainting

[Rui Manuel]

Hi all:

Very recently, I did my first underpainting and, honestly, as my first, I am happy with it.
I am planning to follow to the definitive painting respecting these values.

But before that, it is important me to ask you this: can you please tell me three things that you think are really nice on the underpainting and three others which you consider as big errors?

Thanks for looking.

Rui