Improve platforming feel, add player health/respawn, enemy chase AI, rooms 2–4, and HUD rebuild

godot/autoloads/GameState.gd

@@ -12,6 +12,9 @@ signal resumed
 signal diamonds_changed(count: int)
 signal creations_changed(remaining: int)
 signal timer_updated(minutes: int, seconds: int)
+signal health_changed(current: int, maximum: int)
+signal player_died
+signal player_respawned
 
 # ── Pause ──────────────────────────────────────────────────────────────────
 var is_paused: bool = false
@@ -33,8 +36,11 @@ var creations_remaining: int = 5:
 		creations_remaining = value
 		creations_changed.emit(creations_remaining)
 
-# ── Stamina ────────────────────────────────────────────────────────────────
-var player_stamina: int = 4
+# ── Stamina / health ───────────────────────────────────────────────────────
+var player_stamina: int = 4:
+	set(value):
+		player_stamina = clampi(value, 0, max_player_stamina)
+		health_changed.emit(player_stamina, max_player_stamina)
 var max_player_stamina: int = 4
 
 # ── Difficulty (0 = Easy, 1 = Medium, 2 = Extreme) ────────────────────────

godot/scenes/objects/DeathArea.gd

@@ -11,5 +11,8 @@ func _ready() -> void:
 
 func _on_body_entered(body: Node2D) -> void:
 	if body.is_in_group("player"):
-		GameState.reset_level()
-		body.get_tree().reload_current_scene()
+		if body.has_method("instant_kill"):
+			body.instant_kill()
+		else:
+			GameState.reset_level()
+			body.get_tree().reload_current_scene()

godot/scenes/objects/Enemy.gd

@@ -3,25 +3,47 @@ extends Area2D
 ## Sluggers – Enemy
 ##
 ## A hazard that patrols horizontally between x_min and x_max.
-## Reloads the current scene (player death) when the player touches it.
+## When the player enters detect_range the enemy switches to chase mode.
+## The player can stomp the enemy from above to deal damage; otherwise the
+## enemy deals damage with knockback when the player touches it.
 
 ## Left boundary of the patrol path (world x-coordinate).
 @export var x_min: float = 0.0
 ## Right boundary of the patrol path (world x-coordinate).
 @export var x_max: float = 100.0
 ## Patrol speed in pixels per second.
 @export var speed: float = 60.0
+## Chase speed in pixels per second (used when player is within detect_range).
+@export var chase_speed: float = 120.0
+## Radius within which the enemy switches from patrol to chase mode.
+@export var detect_range: float = 160.0
+## Starting health points.
+@export var max_health: int = 1
 
 var _direction: int = 1
+var _health: int = 1
 
 @onready var _sprite: AnimatedSprite2D = $Sprite
+@onready var _health_label: Label = $HealthLabel
 
 
 func _ready() -> void:
 	body_entered.connect(_on_body_entered)
+	_health = max_health
+	_update_health_display()
 
 
 func _physics_process(delta: float) -> void:
+	var player := _find_player()
+	if player and position.distance_to(player.position) < detect_range:
+		_chase(player, delta)
+	else:
+		_patrol(delta)
+
+
+# ── Movement ───────────────────────────────────────────────────────────────
+
+func _patrol(delta: float) -> void:
 	position.x += speed * _direction * delta
 	if position.x >= x_max:
 		position.x = x_max
@@ -33,7 +55,49 @@ func _physics_process(delta: float) -> void:
 		_sprite.flip_h = false
 
 
+func _chase(player: Node2D, delta: float) -> void:
+	var dir := signf(player.position.x - position.x)
+	position.x += chase_speed * dir * delta
+	_sprite.flip_h = (dir < 0.0)
+
+
+# ── Contact ────────────────────────────────────────────────────────────────
+
 func _on_body_entered(body: Node2D) -> void:
-	if body.is_in_group("player"):
-		GameState.reset_level()
-		body.get_tree().reload_current_scene()
+	if not body.is_in_group("player"):
+		return
+	# Stomp check: player is above the enemy's centre and falling fast enough.
+	# The 50 px/s threshold matches Player.STOMP_MIN_VY; the 8 px vertical gap
+	# ensures the player's feet are clearly above the enemy's collision centre.
+	const STOMP_VY_THRESHOLD: float = 50.0
+	const STOMP_VERTICAL_OFFSET: float = 8.0
+	var player_vel := (body as CharacterBody2D).velocity if body is CharacterBody2D else Vector2.ZERO
+	if player_vel.y > STOMP_VY_THRESHOLD and body.position.y < position.y - STOMP_VERTICAL_OFFSET:
+		take_damage(1)
+		if body.has_method("stomp_bounce"):
+			body.stomp_bounce()
+	else:
+		var knockback_dir := int(signf(body.position.x - position.x))
+		if body.has_method("take_damage"):
+			body.take_damage(1, knockback_dir)
+
+
+# ── Health ─────────────────────────────────────────────────────────────────
+
+func take_damage(amount: int) -> void:
+	_health -= amount
+	_update_health_display()
+	if _health <= 0:
+		queue_free()
+
+
+func _update_health_display() -> void:
+	if _health_label:
+		_health_label.text = "♥".repeat(maxi(_health, 0))
+
+
+# ── Helpers ────────────────────────────────────────────────────────────────
+
+func _find_player() -> Node2D:
+	var group := get_tree().get_nodes_in_group("player")
+	return group[0] if not group.is_empty() else null

godot/scenes/objects/Enemy.tscn

@@ -30,3 +30,12 @@ position = Vector2(0, -31)
 sprite_frames = SubResource("SpriteFrames_enemy")
 animation = &"default"
 autoplay = "default"
+
+[node name="HealthLabel" type="Label" parent="."]
+offset_left = -16.0
+offset_top = -64.0
+offset_right = 16.0
+offset_bottom = -54.0
+horizontal_alignment = 1
+text = "♥"
+theme_override_font_sizes/font_size = 8