More fuel for the fire:
Terran Cross - 100% Kills, No Damage (nice and impossible...maybe this shouldn't count acid/lava damage)
<Weapon> Expert Badge - Awarded during a >=95% finish where 75%+ of the kills came from using one particular weapon type. This would encourage people to try different weapon builds. Probably should exclude pistol and Melee while aggregating shotgun types. Clearly impossible for BFG.
<Weapon> Master Badge - Same as above only 100% finish AND Cybie went down with the same weapon.
Armageddon Award - Nuking 3 levels in one game and surviving (not necessarily beating Cybie). Completely RNG dependent.
Soldier Wings - 2 (or 3?) Master traits in one game (disabled for Ao100).
Hellfighter Medal - Score 10 kills with each weapon type in one game. Melee, Pistol, Shotgun, Chaingun, Plasma, Rocket, BFG, and UNIQUE.