feat: Implement core game managers, player movement logic, and initial UI scenes.

scripts/managers/screen_shake.gd

@@ -0,0 +1,72 @@
+extends Node
+
+# ScreenShakeManager - Handles camera shake effects for impact feedback
+
+var camera: Camera3D
+var shake_intensity: float = 0.0
+var shake_duration: float = 0.0
+var shake_timer: float = 0.0
+var original_position: Vector3
+
+# Shake presets
+const SHAKE_TARGETED: Dictionary = {"intensity": 0.15, "duration": 0.4}
+const SHAKE_GOAL_COMPLETE: Dictionary = {"intensity": 0.1, "duration": 0.3}
+const SHAKE_LIGHT: Dictionary = {"intensity": 0.05, "duration": 0.2}
+
+func initialize(p_camera: Camera3D):
+	"""Initialize with specific camera instance."""
+	camera = p_camera
+	if camera:
+		original_position = camera.position
+		print("[ScreenShakeManager] Initialized with camera: ", camera.name)
+	else:
+		push_warning("[ScreenShakeManager] Initialized with null camera")
+
+func _process(delta):
+	if shake_timer > 0:
+		shake_timer -= delta
+		if camera:
+			var shake_offset = Vector3(
+				randf_range(-shake_intensity, shake_intensity),
+				randf_range(-shake_intensity, shake_intensity),
+				randf_range(-shake_intensity * 0.5, shake_intensity * 0.5)
+			)
+			camera.position = original_position + shake_offset
+		
+		if shake_timer <= 0:
+			_reset_camera()
+
+func _reset_camera():
+	if camera:
+		camera.position = original_position
+	shake_timer = 0.0
+	shake_intensity = 0.0
+
+func shake(intensity: float, duration: float):
+	"""Trigger camera shake with given intensity and duration."""
+	if not camera:
+		push_warning("Screen shake requested but no camera assigned!")
+		return
+	
+	if camera:
+		# If already shaking, reset camera first to get true original position
+		if shake_timer > 0:
+			camera.position = original_position
+		else:
+			original_position = camera.position
+		
+		shake_intensity = intensity
+		shake_duration = duration
+		shake_timer = duration
+
+func shake_targeted():
+	"""Called when local player is targeted by opponent's powerup."""
+	shake(SHAKE_TARGETED.intensity, SHAKE_TARGETED.duration)
+
+func shake_goal_complete():
+	"""Called when local player completes a goal."""
+	shake(SHAKE_GOAL_COMPLETE.intensity, SHAKE_GOAL_COMPLETE.duration)
+
+func shake_light():
+	"""Light shake for minor events."""
+	shake(SHAKE_LIGHT.intensity, SHAKE_LIGHT.duration)