Yup, that seems much better behaved. Spacebar to pause is a nice touch too, I hadn't thought of it, but it really helps since the enemies move so fast that makes it easier to pause and queue up a starting army before they close in.
And yeah, I have no issue with the "Restart" being a "clear progress", just found the behaviour slightly confusing with the layout of the buttons and it kind of looking like it was the start button (since it was kind of paired with "exit"). It not being there does mean I no longer want to click it to start the game lol. Although for some reason I still found myself spending several seconds trying to figure out how to start the game when I loaded up the page again today. If I can figure out why, I'll let you know. (Maybe it was the "Made with Gdevelop" banner darkening the top of the menu, so drawing attention away from the start button, or maybe "start" looks too much like part of the menu title... I'm not sure yet).
UX is both an interesting and irritating field eh?