repterra-web/README.md

REPRTERRA WEB 🦖

A fan-made browser demake of Repterra (Chute Apps / MicroProse) — the base-building survival RTS best described as "They Are Billions, but the horde can fly."

Everything is hand-drawn on canvas at runtime — no image assets, no build step, no dependencies. Plain JS + HTML + CSS.

Play

npm start          # serves http://127.0.0.1:8933

…or just open index.html directly in a browser (works from file:// too).

The loop

1. Grow — Houses raise population cap and pay taxes; colonists arrive at your Command Center and staff Farms, Forester Huts and Quarries.
2. Expand — Generators produce energy and extend your power grid; you can only build touching your grid. Overload it and newest buildings go dark.
3. Fortify — Walls and Gates block ground dinos. Towers shred them.
4. Survive — telegraphed waves attack every couple of days (a warning arrow shows where they'll hit). Roaming packs prowl the map — kill them before day 15, because…
5. ☠ THE FINAL WAVE — every surviving dino on the map charges your Command Center. Lose the HQ and the colony falls.

⚠ The sky is NOT safe

Pteranodons fly over walls, straight for your soft economy buildings. Cannon towers can't shoot up — keep Watchtowers and Rangers covering the air.

⚠ Neither is the water

From day 8 (normal), Suchomimus raids emerge from the lakes — a fully walled base with no waterfront watch is still on the menu.

🦴 Turn the horde into your army

Build a Primal Pen, train a Tamer, weaken any dino below 32% HP and the Tamer slips a capture collar on it. Tamed dinos fight for the colony — right-click to give them a new guard post or order an attack. The Pen heals your pets and each Pen adds +2 tame slots. (A T-Rex is too powerful to tame.)

🥚 Breed them

Park 2+ tamed dinos beside a powered Pen and they'll incubate eggs (60 food each, max 2 per Pen). Hatchlings start small and grow into full-size fighting adults — a self-sufficient dino economy.

💾 Your colony persists

Save from the pause menu, autosave at every dawn, and hit ▶ Continue saved colony on the main menu. Saves are plain JSON snapshots of the whole simulation — world depletion included.

Dinosaur roster

Dino	Threat
Compsognathus	fast swarm fodder
Velociraptor	quick flanker
Dilophosaurus	ranged spitter
Triceratops	wall-crusher (×2.5 building dmg)
Pteranodon	☠ flying, ignores walls
Suchomimus	🌊 amphibious — raids from lakes
Tyrannosaurus Rex	boss, smashes anything, untameable

Plus roaming packs of all of the above from minute one. Day turns to night over the colony (powered buildings glow warm after dark).

Controls

Input	Action
WASD / arrows / screen edge	pan camera
Mouse wheel	zoom to cursor
Middle-drag	grab-and-drag pan
Left click	select / place
Left drag	box-select Rangers
Right click	move order · focus-fire a dino · rally point (barracks/pen selected) · pet move/attack (tamed dino selected) · capture priority (tamer selected)
1–9	build hotkeys
Shift-click	multi-build · hold to keep placing walls
Space / P	pause
F	jump to HQ
Del	demolish selected building (+50% refund)
M	mute
+ / - / 0	game speed 1×/2×/3×

Tech notes

• ~5k lines of dependency-free vanilla JS (js/*.js, plain script tags).
• Isometric canvas renderer with depth sorting, fog of war, particles, animated procedural sprites (every dino/building drawn in code).
• Sim core is DOM-free → fully headless-testable:
  • npm test — smoke suite (~70 assertions: placement rules, economy, pathfinding, waves, power-grid chains, taming & pet combat, breeding, save/load fidelity, victory & defeat paths).
  • npm run balance — scripted auto-player runs full games at every difficulty and reports survival curves (relative difficulty signal).
  • node test/browser.js / test/e2e.js — real-Chromium boot + interaction tests, including a save → reload → continue lifecycle (needs npx playwright-core install chromium-headless-shell).

Fan project for personal enjoyment; not affiliated with Chute Apps or MicroProse.