Not to be too critical but, the fire doesn't look right, too much white. The edges on the dinosaur are kinda sharp. The polar bear has no eyes or nose D: and the .jpg file type makes the text kinda hard to read. I suggest using .png files. Photobucket doesn't convert these to .jpg either like with bitmaps.
Also, if you want to, you could add a bit of shadow to stuff to make it more realistic.
1. Make a copy of the layer you want to make shadowed.
2. Select the object on the new layer and fill it with black. (ctrl+shift+del should have it preserve transparency)
3. Give it a gaussian blur of about 4 or so. The gaussian blur tool changed somewhere between ps4 and cs2, so experiment with this until it looks about right.
4. Now press Ctrl+t to free transform. Right click and press distort. Distort it until it looks right. Remember to make it match the global light.
5. Duplicate the shadow layer and do a gaussian blur on it that's about 10 px. Have it give a nice look to the shadow.
6. Go to the first shadow layer and add a layer mask and use the gradient tool to make it look softer as it gets further away.
7. Set the layer types on the shadow to multiply and lower the transparency on both layers. They don't have to be lowered to the same thing.
8. ?????
9. Profit!
(Sorry, South Park was on and I remembered

)