I can clearly see the M of Mayion has been filled with the bucket tool,the font used doesn't fit too much.
There is no focus point and the effect used for the gun isn't nice at all: it mixes it with the background way too much.
The background looks too plain.
Things to fix:
1) The text,definetly
2) Instead of a white n grey image,try to leave the sniper rifle as the original image is,then edit the background accordignly.
If you're using gimp, render>clouds will do just great to start with.