Hello! I've only just gotten started with this, but I'm really loving it so far. It's great that the seeds are mystery seeds and you only get to find out what they are once you plant them and add them to the book. The pixel art is gorgeous, and I love the amount of thought and detail you put into each plant!
I was surprised by how slowly the hearts accumulate, but as a design decision it does force me to really treat it like an idle game and just let it run in the background (although I've forgotten to water my waxy diamondback a few times already, whoops). Some sort of timer or health bar to show when they next need to be watered would have been a cool addition!
I do have a few early game questions that might be nice to answer in the tutorial at the beginning: what does choosing northern vs. southern hemisphere at the start of the game do? Is three the maximum number of plants before you have to begin harvesting them to make room? If I harvest a plant, can I randomly get the seeds for it a second time or is it gone forever?