Could you give me some constructive criticism?

They are good, but for the sake of being constructive, I would say:

- Study colour theory a little more and look at the relationships between them more closely

- Stay away from the filters, make everything yourself

- Maybe add some braver, more severe shadows and highlights to make everything pop a little more

Really nice work so far though :)

Work on the faces a bit more, the face structures look a bit off.

Those are excellent, really cool, keep up the great work.