Your graphics are so beautiful, loved them! And I deeply agree with the comment above, saying it's interesting that in this game, YOU'RE A HEART, lol. Innovation points from me!
As per how the game works, I had a hard time figuring this out, what was happening, what I should do to, well, see more of the story. And I took some time to notice the "death plants" were not just background, as the "life" TV box, this type of thing. Some sound effects maybe could help with this feedback, possibly.
A small note (and not in the game itself, but that can be nice for people playing it online): there's an option on itch.io to allow people to play in fullscreen. I feel this more immersive -- and also, if you're playing with arrows, a jump won't be confused by the browser with a scroll up command.