You should try to use less colours, 43 colours is completely too much for this kind of graphic and it looses the "pixel art" effect :

= never use .jpg format... always png or bmp...

= try to compensate less colours with more ditherings.

= think like you were using an old machine (Atari ST...)

and so on, otherwise it's not bad at all.

gracias chicos, tenia que editarla y quitarle uno de los desperfectos pero no lo hice aun.

 me encanta la textura, sobretodo la parte de los circulos. buen trabajo

very interesting texture :)

Really nice looking wood effect.

thanks for the comments guys
t3nshi, I write down what you said, the triangular dithering will avoid the next time it also is true that the crack near the lock is not very realistic, will be deleted.
and good with the colors I have a problem now, I will continue practicing!
thanks again.

 This is pretty good for being your first pixel art work! the only things I can notice are that the light part of the wood are too light, and the color doesn't shade well with the base brown, and that the shadows of the metal parts on the wood are a little strange, try avoiding that kind of regular triangle-shaped dithering and using a darker shade of color :3

also, please add a transparent background instead of black ^^

keep it up!

Well done
If this is your 1st pixelart the you surely have talent.
I cant really find any errors. Maybe the crack near the lock is not very realistic for wood.

 Wow this is awesome for one of your first pieces! Color count is a little high but it's a pretty big piece.