Thank you so much for playing Ellie! :) And yes, I agree, it's a bit suboptimal when they're bunched up together like that.
Not 100% sure what you mean by the enemies and their health bar being the same color though? We opted for a classic red health bar as a good contrast to the white background and mostly greenish enemies :)
We are thinking hard about expanding the game in various ways, like adding an economy so you can buy upgrades, new pen types etc. etc. :)