Vibrant animals, big and small roamed over the grey world of Land, Sea and air, however time is running out.

Yep, this isn't a logline at all, sorry. Even if this were not going to be a human story and instead would be an abstract animal-story based thing, usually the animal characters would still be given human qualities of some kind so that their perspective makes sense to humans... usually, anyway.

This is a setting you posted, not a logline for a story.

Who is your protagonist? What is their goal? Who is trying to stop them?

In a logline, it's always better to keep the same tense. You start out past tense then end up present tense. Just something to watch for.

As for the rest LRUS made some valid points, I would take his constructive criticism into account.

Hope that helped, good luck with this!