DOOM + DOOM II

PC Solution (Xbox will need to plug in a keyboard):

Game: Legacy of Rust
Mission: E1M6: The Coiled City
Difficulty: Ultra Violence (for additional spawns)
Difficulty Modifiers: Monsters Respawn

Strategy: Give yourself god mode (IDDQD) and all weapons/ammo (IDKFA) and progress through the level as normal. Once you reach the bottom of the spiral staircase and hit the wall switch (the skull on the pink wall), progress through the wall that opens to the left of the wall switch. Once you enter the center room, the walls will drop and little spiderdemons will spawn. Use the Incinerator (weapon 6) to kill them and they will respawn again after 10-15 seconds. Rinse and repeat.

Video guide:

If you don’t want to cheat (or the ability to get achievements with cheats on is patched out), the devs clearly intended you to get this in E1M6 in Legacy of Rust. Head there with level select, jump down, hit the switch on the center post, go down the spiral stairs and hit another switch.

This opens two paths. You want the one with the Megasphere. At the end of that path is an Incinerator and ammo, and when you take it, Mindweavers will attack you. They’re small, like Arachnotrons, but they shoot bullets rather than plasma, like the Spider Mastermind.

The Incinerator is probably the best weapon to use on Mindweavers generally since they have a high pain chance, near-guaranteeing stunlock. There’s more than enough ammo to kill them all, but if you run out there’s more along the walls of the room.

On Hurt Me Plenty there are six of them, so you can get the achievement in five runs. If you turn on monster respawn, you can get a few more but you’ll run out of ammo before you can get all 30.

If you don’t want to cheat (or the ability to get achievements with cheats on is patched out), the devs clearly intended you to get this in E1M6 in Legacy of Rust. Head there with level select, jump down, hit the switch on the center post, go down the spiral stairs and hit another switch.

This opens two paths. You want the one with the Megasphere. At the end of that path is an Incinerator and ammo, and when you take it, Mindweavers will attack you. They’re small, like Arachnotrons, but they shoot bullets rather than plasma, like the Spider Mastermind.

The Incinerator is probably the best weapon to use on Mindweavers generally since they have a high pain chance, near-guaranteeing stunlock. There’s more than enough ammo to kill them all, but if you run out there’s more along the walls of the room.

On Hurt Me Plenty there are six of them, so you can get the achievement in five runs. If you turn on monster respawn, you can get a few more but you’ll run out of ammo before you can get all 30.