concept iteration

docs/concept.md

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 # Concept
-* DOTA style game but without the heroes (just the creeps) and only in single-player mode (asymetric, not just one player against an AI who can do the same things as the player and has to beat the player).
+
-* setting: science-fiction on the boundary between an asteroid and space
+## Overview
-* display of the game world: 2D (or 2.5D) like Factorio
+
-* Game world has a fixed height but can be scrolled horizontally, the asteroid's surface is on the left and space is on the right.
+A single-player asymmetric game inspired by DOTA's wave/tower structure, combined with a Factorio-style factory builder. The player builds a factory on an asteroid to supply shipyards that produce autonomous combat ships. Those ships fight off endless enemy waves advancing from the right. The goal is to survive as long as possible.
-* The player builds a Factorio style factory on the asteroid. On the edge of the asteroid the player can build shipyards. The factory supplies the shipyards with the required parts to build ships. 
+
-* The ships travel in space to defeat incoming enemy waves (which travels from the right to the left)
+## Setting & Visuals
-* the player owns some small defence stations (drawn twice as big as the spaceship units) positioned in space at some distance to the asteroid that engage incoming enemies (like the towers in a dota match). These stations can be destroyed.
+
-* the amount and strength of the incoming enemy increases over time.
+- Science-fiction setting on the boundary between an asteroid and space.
-* the enemy also owns a pair of defence stations positioned at some distance to the right of the player's defence stations. the player can scroll horizontally only to those defence stations. if destroyed by the player's ships, the enemy strength (thread level) gets doubled (starting with the next wave) and the scrollable area gets extended by a bit and a new set of defence stations (twice as strong as the old ones) is placed at the edge of the scrollable area.
+- 2D (or 2.5D) top-down view similar to Factorio.
-* defence stations drop loot maxbe ship blueprints or Parts blueprints
+- The game world has a fixed height and scrolls horizontally.
-* resourses are gathered by own ships as Scrap
+- The asteroid surface occupies the left portion of the world; space extends to the right.
-* Scrap can be smelted to base mats
+- The number of buildable tiles on the asteroid is configurable.
-* base mats can be mined from asteroid
+
-* building blocks xan be produced from mats
+## Game World Layout (left to right)
-* building blocks are spent to build
+
-* buildings are built in the order they are placed. Building takes time. Only one building at a time
+1. **Asteroid** — factory and shipyards are built here.
-* waves spawn every x seconds
+2. **Player defence stations** — a set of stations positioned in space at some distance from the asteroid edge. They automatically engage approaching enemies. They can be destroyed.
-* goal is to survive for as long as possible
+3. **Enemy defence stations** — a set of stations further to the right of the player's stations. The player can only scroll the view up to these stations. They are the push target.
-* time shall be displayed
+4. **Enemy spawn area** — enemy waves originate from off-screen to the right.
-* number of tile Columbus on asteroid.is configurable
+
-* unlock more asteroid tiles to the left for building . How?
+## Factory
+
+- The player constructs factory buildings on the asteroid to produce materials and ship parts.
+- Buildings are placed in a queue and constructed one at a time; each building takes time to complete.
+- The crafting/production tree is defined in a config file so it can be extended later without code changes.
+- The factory is simpler than Factorio in depth but follows the same production-chain principle.
+
+## Resources
+
+Two sources feed the same production tree:
+
+- **Mining** — the player's starting resource method. Ores are extracted from the asteroid and smelted into basic materials.
+- **Scrap** — collected by dedicated salvage ships from destroyed enemy ships.
+  - Scrap can be smelted into the same basic materials as mined ores.
+  - A dedicated **Reprocessing Plant** building can extract higher-level intermediate products from scrap (with randomised probabilities per product type), bypassing parts of the normal crafting chain.
+
+## Ships & Shipyards
+
+- Shipyards are built at the edge of the asteroid.
+- When the player clicks a shipyard, they choose a blueprint from all currently unlocked blueprints.
+- The shipyard automatically produces one ship of the selected blueprint whenever all required materials are available in the shipyard.
+- Ships are fully autonomous: they travel to the right, engage enemy ships, and do not require player input.
+- If the player's ships are all destroyed, enemy ships advance unhindered toward the player's defence stations and then the asteroid.
+
+## Enemy Waves
+
+- Waves spawn continuously over a period of several seconds, then there is a gap before the next wave begins spawning.
+- The previous wave may still be in transit or fighting during the gap — there is no hard "wave cleared" state.
+- The number and strength of enemies increases over time.
+
+## Push Mechanic (Enemy Defence Stations)
+
+- The enemy owns a pair of defence stations positioned just beyond the scrollable area boundary.
+- The player is **not** forced to push — purely defensive play is valid.
+- If the player's fleet becomes strong enough that incoming waves are trivial, pushing to destroy enemy defence stations provides a new challenge: destroying them **doubles the enemy threat level** starting with the next wave, extends the scrollable area, and places a new pair of stations (twice as strong) at the new boundary.
+- Destroyed enemy defence stations drop loot: primarily **ship blueprints** that unlock new ship types at shipyards.
+
+## Game Over Condition
+
+- There is a **Headquarters** building at the edge of the asteroid (the last line of defence).
+- If enemy ships breach the asteroid — all player ships and defence stations destroyed — they attack the HQ.
+- The game is lost when the HQ is destroyed.
+- Individual factory buildings are **not** targeted or destroyed by enemies.
+
+## Progression & Goals
+
+- The primary goal is to survive as long as possible.
+- Elapsed time is always displayed.
+- New ship blueprints are unlocked by destroying enemy defence stations.
+
+## Open Questions / TODO
+
+- How does the player unlock additional asteroid tiles for building?