I don't think Heaven last hope and the description fit with this game. If you say angels or heaven, I don't really think about 4 cute blobs with different elements. I think about the holy element, and not earth, fire, water and air.
Any other ideas ? The best in our opinion is Accelements but we are not 100% percent if it's best name. Our feelings are like when you go to restaurant you eat very good meal, but it misses one spice and you dont know which one. And below it's another world - Earth Element World
Earth ,Wind ,Water and Fire are also known as the four states of matter. These are the four states that make up the "Material world" You could simply name the world your characters are exploring. It could be called "Materia" Thanks
How about: Seasons Rush? Elemental Rush? Pixie Rush? Fairy Rush? You may also replace the word "Rush" with "Runners" Elemonsters / Elemons Or Pokementals.