Last Horizon — Alien Defense

An idle / auto-battler Alien Defense game: Vampire Survivors decisions on a Missile Command battlefield. Your battery sits on the ground and auto-fires at invaders raining from the sky; you only make decisions — in-run upgrade picks on level-up, and cross-run progression on a Diablo-style paragon tree.

Stack

• Vue 3 + TypeScript (strict, type-strippable) + Vite
• Vue Router (/ menu, /game run, /skills paragon tree, /lab training range, /patch-notes)
• Phaser 4 for the game scene (all sprites generated in code — no asset files)
• Pinia + VueUse useLocalStorage for persistent meta progression
• Tailwind CSS 4

Game loops

In-run (a "run"): invaders spawn across the top in escalating 30s waves and fall toward the buildings and cannons. Each cannon targets its most urgent threat — the one closest to the ground — with predictive intercept aiming, but only inside its range (shown as a faint arc). Kills drop XP gems; each level pauses the game and offers 3 weapon/behavior cards drawn by rarity (common/rare/epic/legendary — higher tiers start near zero odds and grow each wave, boosted by Fortune-branch luck nodes). Every card has 5 star tiers, and every owned weapon runs on every cannon with its own cooldown: flak guns, cluster rockets, tesla arcs, nova pulses, rail guns, mid-air lockdown freezes, angled strafing runs, cloud cover, nanite repair drones, and the BFG. Flat stat growth — and the deep expansion nodes that grant extra cannons, weapon slots, and +1 weapon tiers — live in the paragon tree, not in run cards. Ground impacts cost integrity (one of five buildings collapses per 20% lost); at 0 the base is lost. A speed button cycles the sim ×1 → ×2 → ×5 (sub-stepped so fast bullets cannot tunnel through enemies), and weapon cooldown bars sit bottom-left.

Cross-run: runs award stardust (waves + kills + levels, scaled by tree bonuses, plus interest on unspent dust and per-minute trickle from Reactor nodes). Spend it on the paragon tree — 134 nodes in 7 rotationally symmetric branches (Offense / Arsenal / Tech / Defense / Sensors / Fortune / Reactor), generated from one slot-geometry template rotated through ~51°. Adjacent branches are ring-linked at the fork tier, so you can path around the board without going back through the core. Each branch ends in a keystone that changes how runs start (Executioner, Autoloaders, Overdrive Core, Aegis Protocol, Farsight Protocol, Star Harvest, Capacitor Array). Free full-refund respec; saves from older tree layouts migrate with a full refund.

Prestige: completing the whole board offers a prestige — wipe stardust and the tree, and the camera permanently zooms out to a wider front with one more gun emplacement (up to 10). Weapon pairs unlock synergy tactics (32 so far — see docs/SYNERGIES.md for the full matrix and roadmap), browsable in-game via the ⛓ glossary.

Architecture notes

• src/game/eventBus.ts — typed pub/sub bridging Phaser → Vue (HUD snapshots, level-up offers, run results) and Vue → Phaser (upgrade choice, pause, speed).
• src/game/scenes/GameScene.ts — the entire sim. No arcade physics: movement and collisions are manual squared-distance checks over plain arrays, run in capped sub-steps so the ×5 speed stays accurate.
• src/skills/skillTree.ts — branch definitions + the symmetric board generator, plus the pure functions that fold unlocked nodes into a run's starting stats.
• src/game/data/balance.ts — all tuning knobs in one place.

Run

npm install
npm run dev

Deploy to GitHub Pages

This repo includes a GitHub Actions workflow at .github/workflows/deploy.yml that builds and deploys dist/ to GitHub Pages on every push to main.

1. Push this project to GitHub.
2. In your repository, go to Settings > Pages.
3. Under Build and deployment, choose Source: GitHub Actions.
4. Push to main (or run the workflow manually in Actions).

Live site URL: https://robokozo.github.io/last-horizon/

The workflow sets VITE_BASE_PATH to /<repo-name>/ automatically so the app is served correctly from a project Pages URL.

If you want to test the same base path locally, run:

set VITE_BASE_PATH=/last-horizon/
npm run build
npm run preview

Tooling

• npm run lint — oxlint
• npm run format / npm run format:check — oxfmt
• npm run build — vue-tsc + Vite (Rolldown)