In Waking Mars, you're following the path of an earlier probe. You walk and jet pack your way quickly into the depths. A crew mate and an AI help guide you and suggest ways to use the flora in the caves to advance.
There are no aliens so far, just varied plant life who can be used to remove barriers, create mini ecosystems, encourage growth of new plants.
I find it interesting that you have a health bar, as it seems this is an ecological puzzler. If you fall or a stalactite drops on you, you lose health. I suppose further along in the caves there may be gaseous plants or who knows what peril.