Thanks for taking the time to check this out!
About encouraging more use of the fields, did you use very few of them in the start of the game, and then more later?
And yea the art, I can totally see that. Maybe something a lil more gorey with the plants actually growing into the body could work? So parts of the organs would show and stuff?
Maybe a system where the tile / body actually gets damaged after a bloodbell has been harvested could solve both those. The player would have to use different tiles, since the ones used already had to heal, and it would look way more like it really was in it.
Thanks a ton for the feedback!