Initial commit — Station 0 vertical slice in progress

Includes full design documentation (ARCHITECTURE, DESIGN_NOTES, CONTENT_SPEC, PRODUCTION_NOTES)
and active Godot 4 / GDScript codebase. Core systems built: player, floor generation,
room system, enemy base, body part upgrades, run manager, save system, HUD, EventBus.

scripts/player/projectile.gd

@@ -0,0 +1,89 @@
+extends Area2D
+
+# Set by player on spawn
+var direction:        Vector2 = Vector2.RIGHT
+var damage:           float   = 3.5
+var speed:            float   = 520.0
+var max_range:        float   = 400.0
+
+# Behavior flags (set from player stats)
+var ricochet:         bool    = false
+var explosive:        bool    = false
+var explosion_radius: float   = 64.0
+var explosion_damage: float   = 2.5
+
+var _distance_traveled: float = 0.0
+var _bounces_left:      int   = 1
+var _bounce_cooldown:   float = 0.0   # grace period after bounce to avoid re-trigger
+
+func _ready() -> void:
+	rotation = direction.angle()
+	body_entered.connect(_on_body_entered)
+
+func _physics_process(delta: float) -> void:
+	_bounce_cooldown = maxf(_bounce_cooldown - delta, 0.0)
+	if ricochet and _bounces_left > 0 and _bounce_cooldown == 0.0:
+		_check_wall_bounce(delta)
+	var move := direction * speed * delta
+	position += move
+	_distance_traveled += move.length()
+	if _distance_traveled >= max_range:
+		queue_free()
+
+# ---------------------------------------------------------------------------
+# Ricochet — raycast lookahead to get wall normal before physically touching
+# ---------------------------------------------------------------------------
+func _check_wall_bounce(delta: float) -> void:
+	var space  := get_world_2d().direct_space_state
+	var reach  := speed * delta + 6.0
+	var params := PhysicsRayQueryParameters2D.create(
+		global_position,
+		global_position + direction * reach,
+		1   # collision_mask: walls on layer 1
+	)
+	var result := space.intersect_ray(params)
+	if result and result["collider"] is StaticBody2D:
+		direction      = direction.bounce(result["normal"])
+		rotation       = direction.angle()
+		_bounces_left -= 1
+		_bounce_cooldown = 0.1
+
+# ---------------------------------------------------------------------------
+# Placeholder visual — yellow circle
+# ---------------------------------------------------------------------------
+func _draw() -> void:
+	draw_circle(Vector2.ZERO, 5.0, Color(1.0, 0.85, 0.2))
+
+# ---------------------------------------------------------------------------
+# Collision — differentiate walls from enemies
+# ---------------------------------------------------------------------------
+func _on_body_entered(body: Node) -> void:
+	if body is StaticBody2D:
+		# Wall hit — ignore during bounce cooldown (already reflected by raycast)
+		if _bounce_cooldown > 0.0:
+			return
+		if not ricochet or _bounces_left <= 0:
+			queue_free()
+		return
+
+	if body.has_method("take_damage"):
+		body.take_damage(damage)
+		if explosive:
+			_explode()
+		queue_free()
+
+# ---------------------------------------------------------------------------
+# Explosive — AoE damage to all enemies in radius
+# ---------------------------------------------------------------------------
+func _explode() -> void:
+	var space  := get_world_2d().direct_space_state
+	var query  := PhysicsShapeQueryParameters2D.new()
+	var circle := CircleShape2D.new()
+	circle.radius   = explosion_radius
+	query.shape     = circle
+	query.transform = Transform2D(0.0, global_position)
+	query.collision_mask = 1
+	for r in space.intersect_shape(query):
+		var c = r["collider"]
+		if c.has_method("take_damage"):
+			c.take_damage(explosion_damage)