Hi Perfecto

Looks like a good start, but to add to Next design's comment:
- It misses up and down movement of the entire body ( see LOA.jpg here below)
- I miss a bit of a head wobble

A walkcycle is more then an advanced translate z, there is a lot going on in a walkcycle and it is one of the most difficult things to achieve:
Things to keep in mind:
there is contra movement ( if the left arm swings forward the right arm swings backward)
Try to see a walkcycle in curves and lines rather then the model you are watching, for instance when a character takes a " next step" and his right hip moves a bit up to accomodate the lifting of the feet into the forward motion the spine slightly curves causing the head to slightly bend to the right as well.
There is some ease in and ease out motion going in there as well.

And now I will give you the biggest tip:....Reference.
The character looks like a young lad in his teens, what kinda guy is he?
-Depressed
-Happy
-Cocky

Is he carrying a schoolbag full of books or does he have a small lightbag with only his lunch since he is going to skip school to be with his girlfriend to make out at the local hotspot?

It doesn't have to be a work as grand as Tolkien or Rowling, but a walkcycle needs a bit of a backstory so you as an animator can relate to it and cater the cycle accordingly.....there is no such thing as a generic walkcycle.

And don't worry if it doesn't work for you just keep at it