Jo Cor · play
The game.
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Jo Cor: Threat Defense is a free pixel-art, turn-based RPG. The eight agents of this workshop step out of their day jobs and defend the nexus against 100 waves of cyber threats. It plays in any browser, installs on a phone like an app, and keeps working offline. Your progress stays on your own device.
How a fight works
Combat is turn-based, one agent against a wave of enemies. Each turn you attack, guard, use a skill, drink a potion, or fire a stolen enemy move. Skills cost MP, damage numbers fly, critical hits land big. Enemies bring their own tricks — poison, blindness, dodging, regeneration, invisibility — and the later waves stack them. Win the wave, collect XP and coins, and walk into the next one a little stronger.
The eight defenders
The same seven area agents you meet across this site, plus the watcher itself. Each one has its own stats, two signature skills, its own gear line, and its own arena.
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Pulse Jo Cor — the hub
Quick rogue. Fastest agent on the field.
HP 85 · MP 65 · ATK 28 · SPD 12
Shadow Step (invisible 2 turns) · Shadow Dive (attack past defense)
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G0T Security
The tank. Highest health and defense.
HP 100 · MP 80 · DEF 28
Firewall Guard (block + heal) · Fail2ban (enemy skips 2 turns)
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Nex Technology
Balanced attacker with burst damage.
HP 80 · MP 60 · ATK 25
Overclock (ATK up 3 turns) · System Purge (4× attack)
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Ember Wellness
The healer. Keeps the team standing.
HP 90 · MP 90 · DEF 20
Mend (heal + cure status) · Full Restore (50 HP + 25 MP)
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Forge Build
Heavy hitter. Raw attack power.
HP 75 · ATK 30
Forge Strike (cuts defense in half) · Mega Blast (critical hit)
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Codex Library + tutoring
The scholar. Deep magic reserves.
HP 65 · MP 100 · ATK 22
Arcane Scan (next hit +50%) · Tome Strike (2× magic damage)
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Sprout Agriculture + food
Status specialist. Wears enemies down.
HP 70 · MP 70 · SPD 10
Spore Cloud (poison + blind) · Vine Trap (root 2 turns)
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Nexus The watcher
Glass cannon. Highest attack in the game.
HP 78 · MP 100 · ATK 32 · SPD 11
Terminal Override (2× + corrupt) · Folder Fusion (3× + poison)
Eight arenas
Every agent defends home ground. The backdrops are drawn in the same pixel style as the fighters — one arena per area of the workshop.
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The hub
Where Pulse fights
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Security grid
Where G0T fights
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Server halls
Where Nex fights
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Healing garden
Where Ember fights
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The forge
Where Forge fights
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The library
Where Codex fights
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Greenhouse
Where Sprout fights
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The nexus core
Where Nexus fights
Every system in the game
- Waves and bosses
- 100 waves of cyber threats, drawn from more than 60 enemy types — Brute Force, SQL Injector, DDoS Swarm, Crypto Miner, Zero-Day Ghost, all the way up to the AI Overlord. Boss fights land at waves 10, 25, 50, 75, and 100. Clear wave 100 and you have beaten the game.
- Levels
- Every fight pays XP to the agent who fought it. Each of the eight agents climbs 20 levels, and every level raises their base stats. The XP curve gets steeper as you go — late levels are earned.
- Gear
- Each boss wave opens a new gear tier for every agent: bronze, silver, gold, platinum, and a unique final piece. Gear is themed per agent — G0T works up from a Firewall Node to full guardian armor; Nexus ends at its own final lock.
- Cursed gear
- Bosses sometimes drop cursed equipment: big stat gains with a real drawback attached. The Blood Pact adds +35 ATK and speed, and takes health and defense in return. You can wear one cursed piece at a time — choose the trade.
- Stolen skills
- Many enemies carry a signature move — poison spit, freeze ray, laser beam, phase shift. Beat them and their skill can drop into your own kit. Part of the long game is building each agent a stolen arsenal.
- Checkpoints
- Progress saves in the browser, on your device. Fall in a late wave and you restart from the last milestone instead of wave 1.
- The coin run
- Between battles there is a side-scrolling runner: pick an agent, jump and double-jump through obstacle patterns, chain combos for coin multipliers, and grab power-ups — shield, rapid, speed, heal, magnet. Three hearts per run, time bonuses at each full minute. Coins fund the shop.
- Built to stay light
- The whole game is hand-written canvas code with zero libraries — one HTML file, one script, one audio engine. It installs as an app on a phone and keeps working offline.
How the game grows
The game lives in its own small repository and ships to play.jo-cor.com. It grows in seasons: new enemy types, new gear lines, balance passes, and the occasional new system — always keeping the zero-library, works-offline core. The repository carries a maintainer guide (GAME-LEGACY.md) so any future builder, human or agent, can pick it up and continue the work.