As I played the current version of the game, I realized the Space key (for starting a new round) doesn't work while you're playing the game. That is perfectly fine - since the player at least cannot accidentally reset their score -, but then it means there is only one context when the Space key has a function.
I think you can just show a "press Space to start a new round" message on the screen whenever the player can actually do that. Putting the key in the controls panel is a bit confusing, because it suggests, the key has a less context specific function.
Besides this, the improvements are cool 👍