I think this is quite well known, you don’t dump game mechanics all at once on a new player! The game should ramp up in complexity, and yes this includes UI complexity and features.
I highly recommend looking at the game Plants vs Zombies and talks done by the developer. All the UI and features are well thought through to make the game easily learnable — why plants and zombies? Plants don’t move and zombies walk slowly in a straight line, it’s intuitive. There’s almost no instructions yet players eventually learn a fully fledged lane based tower defense.
This isn’t an ‘education’ problem, it’s a game design and tutorial problem. Look outside of education games.