Hi. I felt like a dummy, having rushed to post my comments after playing for only a short time. After I posted it I noticed that you do indeed get more scan points for the new lifeforms.
I think the swimming controls could use a bit of tweaking, I found it nearly impossible to scan the fish because they are moving around and you are sinking too quickly, or trying to frantically tap up to stay afloat. More buoyancy might make that aspect of the game more enjoyable/manageable. Maybe I'm missing out on a suit upgrade though, I don't think I've gotten all the upgrades yet.
I noticed sometimes the lantern gets caught and left behind in the block above your head while you're digging. Just a minor bug. Also in fullscreen mode I noticed some kind of separation in the tiles. I didn't notice that in windowed mode.
You should make escape key exit the game to a menu (of course these types of things may be getting addressed in the full game, just my observations from what I've played). I got stuck the first time and had to manually force quit because I couldn't figure out how to get out of full screen and exit. I realized afterward F key was what was needed to toggle back to windowed mode, but that's not intuitive.
I think you should limit digging to a shorter reach and not be able to dig on the opposite side of rock. Just a tiny thing that bugged me for some reason :)
Great game though, has lots of charm and fun mechanics. Will be interesting to see what else the full version has in store.
What are you using to develop the game out of curiosity?