Lost In Play Character Design

I tried to design new characters for one of my favorite games "Lost in Play".
I designed a main character and a supposed villain.

In the original game, the main enemy is an annoying little goblin. I explored different ideas for the enemy (I included some small sketched of them in the image I uploaded) and eventually I decided to go for a completely different type of enemy: a bulky angry robot.
for the main character, I designed a small chubby nerd boy.

Basically, I tried to use a round and cute shape language for the main character. He has a round head, round bushy hair (which has some organic feel to it) and his head to body proportions suggest that he's cute and likable. And the opposite is true for the enemy character: It has a lot of sharp edges, all its elements are mechanic, It's big and angry (I designed the antenna on its head to look like a frown), and He has asymmetrical arms and legs. all of this design choices helps the fact that although It's a humanoid robot, It's very different from the main character.