In unlimited mode, we should have an achievement for a combo score of over 20.0million within an hour-and a half, or 100 minutes, wouldn't be too hard to get in the game, because if you end up setting things up right or on accident, turtle shells will be trapped into some huge horde against the ceiling, and the turrets and blades won't stop hitting them, so it'll just keep going.
Or maybe an achievement of all three valves having a level of 100 each, saying "Really, do you need that many turtles to pop out that fast?!", or something!
I cried when I was told it was a lie. When I finished, I began to cry so heavily. I didn't understand the game at all, but, the comment above, helps, me understand it!