Level eight is by far the most difficult level in the game. It took me quite a while to get past harder mode because of just this level. All of the other levels are extremely easy to moderately easy. Thankfully, I was able to complete level eight of hardest mode quickly, which actually meant I spent much more time on harder than hardest. The medals are clearly undervalued. I mean, I was the first person to get two of them in four years! seven, before that. It's definitely not worth completing for forty points, which may be the reason why so few people have even tried to get them.
I believe that "Number 1" is broken, but I have no way to prove it since there isn't any leaderboard with a leader with whom I may compare my times.