The drawings look OK but I'm afraid this is one of my very first bad comments. The colouring is not good at all. 15 minutes is not a good time to spend drawing something even if it's not finished. Maybe add some shading, a layer or just take more time, whatever works for you. I will give you some good points, the drawing looks quite fine, the grey bits. Colour using a finer pen. Sorry, I do not intend this to be mean, just advice. I saw all your other pics and I love them!!! I don't know what went wrong with this one, maybe cos it's not finished, I hope it's just that.