I really love the game so far!
One thing I'd love to see is the ability to check up on the data you've collected, and perhaps name your discoveries.
Things like looking up the planet maps, the list of known species on those planets, details of each species,... The game is mostly about exploring after all!
Another thing I'd like to see is a more consistent biodiversity on each planet. Aliens from the same planet should share a common ancestor or two, to make them similar enough to be widely different from aliens from another planet.
Example: Planet X has 3 main groups of creatures: Avians, mammals and insects.
The mammals come in two big groups: tripedal and tentacled.
The tripedal mammals come in the scaled and feathered varieties, each with their own subdivisions for predators, prey and perhaps a sentient species or two.
The tentacled mammals happen to be all furry, but there is a subgroup with a flotation bladder.
The other groups also have their own subdivisions. The more cosmetic traits can be added more loosely, like eye shape and neck length. (but not eye type or number of eyes)
This mimics earth in that almost all land-dwelling vertebrates have 4 limbs, divided in avians, reptiles and mammals. Each group can then be split in other groups and so on.
I think that this way each planet would get it's own signature biodiversity, which could become very noticeable and interesting if you are able to name and catalogue these creatures.