I loved this game!! I played for a really long time. A little tutorial would be nice, as it took me a second to figure out how the eating mechanic worked, and I died a couple times before figuring out about health seed regeneration.
I would definitely recommend a stat window of sorts, as once you start getting more and more plants, it is tough to figure out what you have going for you (your base stats, planted buffs, and eating buffs really start to stack!)
There are a couple balancing things I would look at too, as well as a little trick with the acorn mages, where you eat/plant a bunch of magnet seeds and farm the acorns the mages spawn, getting tons of loot without exploring. Damage buffs also take you incredibly far, and I could 1-3 shot most enemies a bit into the game. You wouldn't have to nerf the plants per se, but maybe add new monsters or leveled up versions of the starting ones that show up later on.
I had so much fun with this game and I couldn't stop playing it! Incredible job!!