Digital Art - Critiques/Advice

Well, my parents got me an 8x6 Wacom Intuos for Christmas and I finally got a chance to use it yesterday. I came up with a couple variations on the same basic picture.

Which do you like better? Why? What would you do to improve them? Any tips to make my overall drawing style better?

Don’t hold back if you have constructive criticism, harsh or not. This is pretty much my first drawing with a graphics tablet, so I realize it isn’t perfect, but I’d like to do my best to improve.

Thanks,
Cody

(Pictures attached)