too casual sounding... cartoons are bright, vibrant, and punchy, so you want a lot of pizzicato and surprise strikes.

to end it, try a focused sound that evolves into a black hole. like a void of noise not being there.

silence is a very useful tool, and you need to appreciate the cause and effect. the thing that is wrong with this piece is that it has no direction. its lofty and chords, thats it.

TL;DR

make it punchier, have some fun, use silence as a way to tell people that its over.

the notes mixed together didnt exactly fit the right key
you should look up music theory, it basically teaches about piano notes and what notes work with what
however most idiots just make a video saying ''these notes with these work and that all you need, put notes together till it sounds good and thats all''
if you want i can send you a midi or some piano notes and you can try and learn from it