A survivors-like deckbuilder with mutating spells and five schools of dark magic. Build devastating combos, battle through ten cursed levels, and spend earned points on booster packs. Survive the isometric bullet hell solo or in local co-op.

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Early Access Game

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Note: Games in Early Access are not complete and may or may not change further. If you are not excited to play this game in its current state, then you should wait to see if the game progresses further in development. Learn more

Leaving Early Access: 24 Sep, 2026

What the developers have to say:

Why Early Access?

“Since the game is made using AI, we are able to iterate on changes and add new content very quickly — which we are already doing, mainly by incorporating feedback from players and beta testers on our Discord server. We want CODEX MORTIS to be entirely community-driven, and before we finish the final version, we want to build it together with you, because we see that a lot of content, mechanics, and new worlds will turn out better when based on your feedback.”

Approximately how long will this game be in Early Access?

“Approximately six months — we expect that during this time we will gather enough feedback and ideas to complete the final version.”

How is the full version planned to differ from the Early Access version?

“We plan to add additional worlds and levels, more spells and more synergies, as well as online multiplayer.”

What is the current state of the Early Access version?

“The game is completely playable, contains dozens of hours of gameplay content, and 8 full gameplay levels - basically, all features and content mentioned in "About" section. ”

Will the game be priced differently during and after Early Access?

“We're not planning on changing the price when we leave early access.”

How are you planning on involving the Community in your development process?

“We want to engage the community the way we already do — by collecting feedback from Discord, introducing surveys, and encouraging discussions about ideas on both the Steam Community forum and Discord from day one of Early Access.”
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About This Game

Codex Mortis is an isometric horde-survivor bullet hell whose roguelite loop runs on a spell deckbuilder. You play a necromancer. Before every mission you assemble a deck from the spells you own, then carry it into a battlefield filled with the undead, alone or with a friend in a local co-op. You spend the points you earn during a run on booster packs, each pack adds new spells to your collection, and those spells open builds you could not have assembled before.

BUILD YOUR DECK, OPEN YOUR PACKS

Plan before you slaughter, because once the mission starts you fight with what you brought. Before every mission you assemble your loadout from the spells you own, and that loadout is your deck. A deck weighted toward Summoning wins the field by crowding it, with skeletons soaking the horde while you cast. A deck weighted toward Blood Magic hits harder and sacrifices your life to do it. 

The points you earn on a run buy booster packs, and every pack adds spells to your collection, so your next deck comes out of a wider pool.

TWIST YOUR SPELLS WITH MUTATIONS

Mutations sit on top of the skills you carry and change the way they work. A mutation riding your bone spear sends it out in a pattern you have to learn again, and one on a summon calls up another archetype of undead. Others reshape the ground an area spell covers or give an aura a character of its own, so a spell you have cast a hundred times comes out of your hands changed.

FIVE SCHOOLS OF DARK MAGIC

Every spell in your collection belongs to one of the five schools of dark magic.

  • Necromancy: bone spears, corpse explosions and skeletal prisons.

  • Summoning: raise undead armies and bone golems.

  • Blood Magic: sacrifice life for power.

  • Soul Magic: harvest essence, phase through enemies.

  • Curses: break enemy will, spread terror and confusion.

TEN LEVELS, 3 GAME MODES

Find perfect builds for ten levels available in Early Access: Forgotten Graveyard, Sand Tomb, Cursed Catacombs, Bone Cathedral, Void Sanctum, Soul Nexus, The Throne Room, North Pole, The Overgrown Grave, Chapel of Perpetual Bloom

INFINITE BUILD VARIETY

  • Mix active spells across magic schools for unique combinations

  • Command Heroes with their own abilities (or play co-op with friends!)

  • Equip Artifacts that grant powerful bonuses

  • Deep progression - upgrade damage, cooldowns, health, speed, and more

  • Open card packs for new spells

  • Procedurally generated worlds - every run is different

AI Generated Content Disclosure

The developers describe how their game uses AI Generated Content like this:

AI is used for entire code of the game, text, arts, sounds and music.

System Requirements

Windows
SteamOS + Linux
    Minimum:
    • Requires a 64-bit processor and operating system
    • OS: Windows 11
    • Processor: Intel Core i3-2100 / AMD FX-4300
    • Memory: 4 GB RAM
    • Graphics: NVIDIA GeForce GTX 650 / AMD Radeon HD 7750 / Intel HD Graphics 4000 / 1 GB VRAM
    • Storage: 140 MB available space
    • Sound Card: Any
    Recommended:
    • Requires a 64-bit processor and operating system
    Minimum:
    • OS: Ubuntu 20.04+ / SteamOS 3.0+
    • Processor: Intel Core i3 / AMD Ryzen 3
    • Memory: 4 GB RAM
    • Graphics: Vulkan 1.1 compatible GPU
    • Storage: 140 MB available space
    • Sound Card: Any compatible sound card
    • Additional Notes: Native Linux build
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