Love your idea of the perspective of the player as a drop of water playing with the idea of environmental dominance. The art style is playful yet mysterious which is perfect to what you're going for. I would recommend having the encounters and story aspects planned out sooner rather than later to ensure they're all cohesive to the story of this droplet. This gives me "We Have To Go Deeper" vibes with the style of game you're going for and I love it! I can't wait to see how this develops!