DOOM Eternal — Achievement Walkthrough

Glory Kills (the melee finishers on stunned demons) have unique animations per demon type and per direction/limb. Just Glory Kill lots of different demon types from different angles — the game counts unique animations. 33 comes naturally over a couple of levels since each demon has several finisher variants.

Sentinel Crystals are found in levels; spend one at a suit station to raise Health, Armor, or Ammo capacity. Do it once for this. You'll find your first crystals in the opening missions.

Cumulative demon kills — you'll blow past 666 just playing the campaign normally (each level has hundreds of demons). No action needed beyond playing; it pops mid-campaign.

Slayer Gates are optional, very hard combat arenas (one per level, behind a red-key barrier). Complete one: survive the brutal wave fight and grab the Empyrean Key. Go in fully kitted, keep the combat loop flowing (Flame Belch for armour, chainsaw for ammo, Blood Punch), and prioritise the most dangerous demons. Just one gate is needed for this (all six = Breaker of Gates).

Praetor Suit points (from field drones / floating suit tokens) buy perks in categories (Exploration, Combat, etc.). Fill out ONE whole category. Grab the suit tokens in levels and dump them into a single category to complete it.

Sentinel Batteries are collectibles in levels; back at the Fortress of Doom hub you spend them to unlock rooms/rewards. Collect and spend 8. Each level typically has one or two batteries — grab them as you explore and redeem at the Fortress.

Extra Life collectibles (the little 1-UP Slayer figures) are hidden in levels and refill as you progress. Collect 20 total across your playthrough — grab every one you see while exploring; they double as free revives in combat.

Pick ONE category (Health, Armor, or Ammo) and pour every Sentinel Crystal into it until that track is maxed. Collect all the crystals you can (explore for them) and focus them on a single stat. You don't need to max all three — just one full track.

Finish the base campaign on any difficulty — the hidden mission-completion achievements (Doomsday, Interplanetary Fracking, Regime Change, Cross the Threshold, etc.) unlock as you clear each level, so a full playthrough earns the whole story set. Play on 'Hurt Me Plenty' or lower if you just want completion; difficulty doesn't gate any base achievement. Keep moving, use the Flame Belch for armour and chainsaw for ammo — the combat loop rewards aggression, not cover.

Clear all six Slayer Gates — the hardest standard content in the base game. Each is an intense wave arena. Tips: fully upgrade before attempting, master resource management (Flame Belch, chainsaw, Ice Bomb to freeze crowds, Blood Punch on heavies), and learn each gate's demon spawns so you can pre-empt threats. Expect retries; you can attempt them on a lower difficulty to make it easier.

Buy every perk in every category. This needs most/all Praetor tokens in the game, so explore thoroughly and collect them all. Use a collectibles guide + mission select to grab any missed tokens; by the final missions you should have enough for all perks.

Codex pages are lore collectibles hidden in levels. Gather every physical page in the base campaign (there are separate versions of this achievement for the two Ancient Gods DLCs). Use a collectible guide + Mission Select's per-level tallies to find the ones you missed.

Cheat Codes are collectibles hidden in levels; collecting them unlocks fun modifiers you can toggle on for replays (they disable achievement progress while active, but simply COLLECTING them is what counts here). Find every cheat-code pickup across the campaign with a location guide.

Album collectibles (vinyl/soundtrack records) are hidden in levels and unlock tracks in the Fortress jukebox. Find them all. Same approach as the other collectibles — a location guide plus level replays via Mission Select.

Toy figures (the little Doom-character collectibles) are scattered through levels and displayed in the Fortress. Collect every one. Use a guide + Mission Select to track down any you skipped; nothing is missable.

Find every Sentinel Crystal across the campaign. Use a per-level collectible guide and Mission Select (which shows collectible counts per level) to clean up any you missed. Nothing is permanently missable — replay levels to 100% the crystals.

Each weapon has two mods, and each mod has a Mastery challenge (e.g. 'kill X demons with the mod a certain way'). Mastering ALL of them is a big task. Buy every mod with Weapon Points (from drones), then complete each Mastery challenge — many can be knocked out in the Fortress ripatorium or by replaying combat-heavy levels. Some masteries are fiddly, so target them one weapon at a time.

Horde Mode (a free update) is a score-based survival mode. Complete its first mission — play through the waves and finish the run. Bring your combat fundamentals; it's standard DOOM combat scored across arenas. (Beating full Horde Mode = Game Over.)

Over the campaign you (re)acquire each weapon as you progress. Once you've obtained the full arsenal, this unlocks. Essentially story-driven — keep playing and you'll collect them all; the last weapon comes late in the campaign.

Once you've collected the Famine cheat code, start a Mission Select run with ONLY Famine active (no other cheats). Famine stops demons dropping health/armour/ammo, so lean hard on the chainsaw (ammo) and Glory Kills/Flame Belch (health/armour) — the combat loop still supplies you. Pick an easy, short mission and finish it with just that cheat toggled.

Finish the entire Horde Mode. It's a gauntlet of combat and bonus rounds — keep the resource loop going and don't get greedy. Play it after you're comfortable with the campaign's combat; the demons and arenas are familiar, just relentless.

Queue BATTLEMODE as the demon side and use a different playable demon each time until you've played 5 different ones (Revenant, Mancubus, Pain Elemental, Archvile, Marauder, etc.). You can pick the demon before matches — rotate through five and it unlocks.

BATTLEMODE is the 1 Slayer vs 2 Player-Demons PvP mode. Just PLAY 25 matches (win or lose). Queue up and play them out; this is the gateway to the other BATTLEMODE achievements (Blood Bath, Fight Like Hell, Mix and Match, Weapons Expert), which you'll progress while getting your 25 matches in.

Cumulative kills in BATTLEMODE (as Slayer, killing demons; as demon, killing the Slayer). 200 takes a good number of matches. Play the Slayer for reliable kills if you're skilled, or grind demon-side objectives. It stacks while you complete Man vs Monsters (25 matches).

As the Slayer in BATTLEMODE, land a killing blow on a Player-Demon with each of the 8 weapons (Combat Shotgun, Heavy Cannon, Plasma Rifle, Rocket Launcher, Super Shotgun, Ballista, Chaingun, BFG). Deliberately switch weapons to grab the final hit with ones you haven't used yet. Track which you've done and target the finishing blow with the missing weapon.