4 Difficulties: Easy, Normal, Hard, & Brutal.
3 Bosses: Sombra, Sigma, & Symmetra.
2 Dungeons: Dorado & Havana (which is not finished yet).
1 Clown: Lillmy#2200 (EU)
Outsmart the Infiltrator, Sombra. Then fight the Psychic Guard, Sigma and finally challenge the Photon Magistrix, Symmetra.
After each boss your team gains loot which could be distributed strategically, or just take everything yourself.
After Sombra is defeated, moving close to her brings up a hud that gives information about upcoming bosses.
Probably has a few bugs, but the mode is still playable.