At the moment the whole thing hints the cartoon but doesnt resemble it well.
I would suggest you studying the style used on Tom and Jerry before you continue working on this.
Both character and enviroment wise.
You said you are using pastel colors following the cartoon stylistic choices, but yours dont have that "painted" feeling, your tiles just look washed out.
Look how the cartoon's dirt was made mixing yellow with green, brown and turquoise tones, look how the rocks were made mixing gray with purples and blues and yellows, look how the grass mixes blues and yellows.
You should experiment with colors rather than just using pastel tones.
As for Jerry, you should pay more attention to the shapes used on the structure of his body, use references (model sheets, cartoon screens, whatever), sketch them down on paper (or your computer) and try to pull the likeness.
I'm aware that making pictures that resemble cartoons in such a small space is hard, but you should try to go as close as you can.
I made a Jerry myself, hoping it would serve you as a reference, some details might have not been translated that well, but didnt have much time to work on it (20 mins?)
Anyway, looking forwards to more updates.
Good luck with it
