I didn't thought I'd find another story about sentient plants for this jam LMAO ! For a single synth submission it's diverse enough in the sounds, but it's not in the chords departement. You can make your synth shine by making more with your harmony and melo, it's a necessity in minimalist music such as yours.
You also need to chase "fulness" as much as possible, some parts sounds a little hollow : a good way to resolve this issue is appropriately to write counter melo and richer harmonies, so really if I had one advice, dig this part of music theory !
Anyway, GG, and sentient plants (with visuals !) for the win !