Is it possible to beat all levels with free heros

so i have alsways wonderd could you beat all of the levels of coco with only tharin or would i have to use a least the sub heros or would i have to use some of the heros that you buy with gems

No, it is not due to the fact that some levels require certain hero’s to even attempt, like the Ritic ones in Kelvantaph Glacier

well i mean baring those levels that need a certain hero to play would it be posible

I don’t see why not.

It is possible for most levels, however, there are some levels that require a wizard for casting haste (serpent savings), and also some levels that need speed (alpine rally)