Hey Melodee, let me ask you something.
In ur last version, where is ur light source?
It would be a good exercise to post it again on a larger canvas and draw a circle with an arrow to represent the sun/light angle.
I'd say do that without editing the sprite.
Then we can work on ur shading.

Try "painting" more roughly with larger brushes don't worry about messy pixels.
Just paint the silhouette in a solid base colour and clean the edges a little.
Then paint in the very darkest bits all in one colour.
Then add the next shade and block it all in to make the forms.
Add another colour for lighter areas and another much brighter one for highlights.
Only use a few colours and try to express the forms in confident blocks.
U dont want to try to shade or blend for this type of excercise.

Until ur eye is trained, it helps to reduce the reference image to a low colour count as this will show u much more easily but try to pay attention and learn to do it by eye.

Just quickly, I like this but the backgrounds are too distracting.
I think the floor tiles are too small (detail) and repeated, and still have too much contrast.
The grid effect is not only overkill but it also confuses the actual gameplay grid.

Be aware of the general rule that the more detailed, contrasting and saturated something is, the more it attracts the eye.
Generally you would want characters and items to really stand out.

Just wondering if such a thing exists.
I mainly use photoshop but can't view the images from devices such as my mobile or some computer that i cant install software on.

Thanks 

Good effort with the texturing but really u should focus much more on communicating the forms using stronger light and dark before getting into pixel level detail.
Texture really must follow after form and lighting.
To quote Cyangmou "major form > minor form".