You can ONLY win Planet Apocalypse by killing the Lord. The core game’s Lord is Baphomet. Unlike some other co-op games, you’ll want to attack the lord several times during the course of the game. If you wait till the end, then gang up on Baphomet (or any Lord), you’ll simply lose. They are just too tough to take out in a single fight.
Fortunately, they don’t heal up between fights (with a few exceptions), which means you can zip in for a strike, fight the Lord until you are on the ropes, then run away to heal up, gather more courage & troopers, then return for another bout.
This lord is basically a giant goat skull attached to a wall. Well, there’s more to it than that, but this is the basic situation. All lords have what is called a Menace and a Reward.
The Menace triggers when the heroes enter Hell Time to fight the Lord. Baphomet’s Menace is that he gets an immediate attack. Since he starts off rolling 6d12, that’s not trivial, and you’ll want to have some troopers along to soak up that damage.
Baphomet’s Reward is that you can earn courage if you damage his Wall. Baphomet’s Wall is part of his set up. When a hero rolls attack dice, he can either hit the Wall or Baphomet itself. Destroying the Wall isn’t strictly necessary. It is, however, helpful, for two reasons.
First, there’s that Reward courage. It’s always nice to earn courage – if only because you can use that courage to help other players later on in the battle, giving them a better chance to hit the lord.
Second, if you manage to destroy the wall, then Baphomet’s attack drops from 6d12 to 6d8, which is FAR more survivable.
Baphomet is fairly tough – a 6 (the same as a Fiend), which means some heroes may not be able to hurt him unless they get help. Another problem with Baphomet is that if you are injured by him, you get set on fire.
Fortunately, while you are fighting the Lord, time doesn’t pass, so your Fire markers won’t actually cause any damage. But if you are forced to retreat, you’ll need to spend time extinguishing the flames of course.
Baphomet, as you’d expect, is one of the easier demon lords, because he’s the basic core game lord. “Easy” is relative, and he is still hard to beat, and if you succeed, you should feel proud of yourself.