Any ideas for "feat of strength" community campaign achievements in AoE 2, where you go above and beyond normal campaign requirements?

I got idea from SC 2 where in original wings of liberty there were secret "Feat of strength" achievements in the campaign for certain missions where you'd have to, for example, destroy all enemies in a mission where you normally just have to complete 1 objective.

Some of my own ideas were:

Arabian Nights - Unlocked by defeating all enemies in mission 6 of the Saladin campaign on hard difficulty or harder.

We Need Not Siege! - Unlocked by destroying all enemy military buildings in mission 1 of the Le Loi campaign on hard difficulty or higher.

2 examples from sc2: You'ze So Crazy - Unlocked by destroying all the Protoss forces during the Welcome to the Jungle mission on normal difficulty.

Monster Mash - Unlocked by using the ARES machine to kill the Brutalisk in Piercing the Shroud on normal mode.

Would love to hear if anyone else has ideas for good challenges!

Tl;dr: Suggest a "Feat of strength" achievement where you go past normal campaign rules to do something harder (such as defeating all enemies before a time limit or instead of completing normal objective).