It's clear you're going for a cartoony style, so the best advice in my opinion would be doing research on various cartoons. There's a strong chance you won't invent anything new (I may be wrong though, you never know), so just try out various styles.
For example Adventure Time uses small eyes and puts them far from eachother and very close to the mouth.
Old cartoons would go for long narrow eyes close to each other.
You could also research how other games dealt with the problem. You obviously aim for a big head - small body style. Maybe you should check out other games which also chose this style. Zelda? Pokemon for Gameboy? Spelunky maybe?