Hey I was wondering if I could base the game around a pizza theme? Artstyle wise!?

Well they specified in the game jam post that "The theme is not pizza. If you make your game about pizza you will be disqualified."
I'm not sure about the art style thing, though.  
I guess you should just try not to show pizza too much!

you can include a pizza if you absolutely need to, the game just can’t be ‘about’ pizza, just don’t push it!