Last night we took turns trying to survive in Left 4 Dead 2 for four minutes using only a melee weapon.
This other guy got it before I did, so we spent the rest of the night with me trying to last 4 minutes using only the sword.
Finally, we did it, but I didn't get the bleep bloop. I thought it was because I used an adrenaline, so we tried again.
This time I didn't use any adrenaline or anything, and we finally beat 4 minutes, but again, I didn't get the bleep bloop. So we figured out the medal minimum was no longer 4 minutes, it had switched to our best time (which was 5:17, when we beat it for the other guy).
So we tried again, finally beating 5:17. But I still didn't get the bleep bloop because it turns out that isn't actually a medal... we would have to last for 7 minutes. So we figured out we would need to change maps.
We tried a lot of different maps before finally beating it after a few hours of attempts. The whole time I kept screwing it up because I would get incapacitated and accidentally shoot my pistol because it automatically switched me as I went down.