Thank you for your input! I've made a small update to make it clearer how to change elements and use them when you unlock a new one.
You basically have to aim with the mouse to where you want to interact, whether it is an elemental block or an enemy. Different elements have different effects on elemental blocks, for example, using the air element on a fire block creates a tunnel of hot air that elevates you.
I leave discovering the rest of the interactions to you 😉.