Well, a few points of criticism..
First of all the 'Guild Wars' is kinda dull. I don't know what programme you use (I assume phtoshop?), but I would either give it an more yellowish outer glow or inner glow, or maybe even both, other otherwise just cut out the logo of guildwars from somewhere and use those letters.
Secondly, the greenish thin you put in it. Its not bad, just (I assume you work in layers) put the layer where the greenish stuff is in, beneath the one with your assassin and the GW2 logo; it makes it stand out your assassin more (now the dagger he is holding is almost unnoticable).
Thirdly try to render the main object in the work better (in this case that would be the assassin). Its cut out a bit pixy, you can see sharp corners everywhere. Using a eraser brush with lower opacity / lower flow, will make it alot smoother (just for the edges, for the rough errasing work just use full opacity and flow). Then secondly, duplicate the layer of the assassin, and change the layer effect of the top layer to overlay or multiply (whichever looks nicer) and then start playing with the opacity or that layer. This will gives you a smoother looking, bit darkenened and more alive looking work.
Hope this helps, if you dont understand some terms I would be more then happy to explain them
EDIT: Quick thing I did to show you what I mean with the Smoother look and the Multiply layer. Dont mind some parts of the rendering, was done in 5 minutes