Thanks so much for such thoughtful feedback! And even bigger thanks for the bug spot, you're right; basically I had a debug script that showed it on-screen like a stopwatch, so at 60 seconds a minute counter would tick over and it'd reset. I'd just copied and pasted that seconds script straight into the game-over screen so it always reset to 0 at the minute mark. That's been patched (and added decimals in-case two people had some close-call); was a single line!
Thanks again!