Didn't get to play this yet, but FYI:

You can't sideload .rar files to the playdate. The sideload page only allows .zip files.
Obviously this can stil be circumvented by just extracting the rar file and making a zip file out of it, but it'd still be appreciated if you could upload this as a zip file ;)

Had trouble finding bacterium for a while, and a few cases where they just up and disappeared part way through cataloguing.

That said, definitely some potential here for a fun and interesting game, maybe even some educational avenues as well.