Me and my group initially wanted to get Ark Nova but two of us got to test it and both didn't really like it. Then we found Earth and fell in love with it. It also features a huge replayability.

On the central board, 4 animals get drawn randomly. These set "milestones". Players that fullfill their requirements can claim the card. If your're first to claim it, you gain more points than the later players. Also two ecosystem cards are drawn randomly, that award points for specific ways that you have built your grid. All of these cards are double sided, so we usually toss a coin for each one to determine which side gets chosen. Then each player gets an island card, a climate card and an eco system card. As they're double sided, each player gets to choose for their own, which side gets placed on their tableau (and thus, which actions they allow or which player specific bonus points are active, how many ressources they start with,...).

This setup is really variable and every game forces you to rethink and build a new strategy. Also almost every ressource in the game is worth victory points, which means, that there are tons of ways to gain (and exchange/lose) points. No two games feel the same.

Oh: And there's no downtime, as everyone gets to participate in the other players turn and also gain ressources / activate their cards. At least after a few rounds, when everyone is able to play in parallel. In the beginning, I recommend to take turns, so that everyone can learn from your actions and also everyone is on the same page interpreting the rules, etc.