Thank you so much for the feedback, I'm honestly humbled!
Great tip with the is_action_pressed, and you're right, I did use is_action_just_pressed. I had felt it wasn't responsive enough but I decided to stick with it as it work okay, with the intention of returning to it, but of course I didn't have time.
And I apologise for the unclear instructions, the short intro and controls were pretty much the last things I added.
Thank you again for the feedback, I'm thrilled you enjoyed it!