Right now almost all elevators go down. Only the "middle break" levels, and the "return to Haven" elevators go up.

What I'd like to see: Each floor has both an up and a down elevator at the other end. You can choose to go in either direction, and the party can split up at any time. Equally, just as parties can split by going in different directions, they can merge if two different parties go onto the same floor within a few seconds (60? 30? 90?) of each other. This will enhance the "massively multiplayer" feel of the game.

The benefits of being able to up or down? First, after 6 or 7 levels, you probably have lots of vials and vitapods. You're probably still going strong and not in a hurry to end it all. Being able to stay in, and move around a bit more, would be beneficial.

Additionally, a third option is "Move to the next level on this floor". If floor construction continues to be horizontal and not vertical, then being able to run multiple levels on a single theme will benefit from being able to move horizontally on a single floor.