I get sad, impressed and excited when I see a piece like this with a description like the one you've given.

Sad: Because what you've done in 30 minutes is what I might be able to achieve in a day or two (but that's why I keep practicing :))

Impressed: Because the paiting, the brushstrokes, colorpalette, clear and conscious choices where to put detail to give depth are all spot on.

Excited: Because it all comes together ito such a nice, atmospheric piece! As I said, the choices where you've put emphasis on detail really pushes the arm into the foreground and the face into the background. Still the natural focalpoint is on that amazing helmet and there is such a nice threading of where you've put highlights and shadow that I sense my brain adding pieces to complete the charecter in spaces where there is only black. Amazing work.

My main grudge is that you only spent 30 minutes and that's why there are areas that could be refined more. Motivation to 4.5/5. Really cool though.