Initial commit: Godot 4.7 pixel platformer prototype

Player: move/jump (Space), test flight (F, debug builds only). Key: pickup, hold S to aim with live trajectory preview, release to throw, W to warp to the thrown key. Spring bounce. Spikes deal damage. 3-heart health, Z consumes a heal item for +1 heart and a 5s shield. HUD with hearts and item count. Death screen with fade-to-black and restart. Hidden passages. Assets: Kenney Pixel Platformer (CC0).

scenes/prefabs/interactables/spring_red.tscn

@@ -0,0 +1,30 @@
+[gd_scene load_steps=5 format=3]
+
+[ext_resource type="Texture2D" path="res://assets/game/interactables/spring_red.png" id="1_texture"]
+[ext_resource type="Script" path="res://scripts/spring.gd" id="2_spring"]
+
+[sub_resource type="RectangleShape2D" id="Shape_spring_body"]
+size = Vector2(16, 10)
+
+[sub_resource type="RectangleShape2D" id="Shape_spring_trigger"]
+size = Vector2(18, 14)
+
+[node name="SpringRed" type="StaticBody2D" groups=["spring"]]
+collision_layer = 1
+collision_mask = 0
+
+[node name="Sprite" type="Sprite2D" parent="."]
+texture_filter = 1
+texture = ExtResource("1_texture")
+
+[node name="Collision" type="CollisionShape2D" parent="."]
+position = Vector2(0, 3)
+shape = SubResource("Shape_spring_body")
+
+[node name="BounceArea" type="Area2D" parent="."]
+collision_layer = 8
+collision_mask = 2
+script = ExtResource("2_spring")
+
+[node name="TriggerShape" type="CollisionShape2D" parent="BounceArea"]
+shape = SubResource("Shape_spring_trigger")