added switches and spikes (closes #6) and puzzle 3 (closes #34)

assets/levelList.json

@@ -58,7 +58,7 @@
 		"levelFilename": "puzzle<n>.json",
 		"levelDisplay": "Level <n>",
 		"levels": [
-			1, 2
+			1, 2, 3
 		],
 		"nextLevel": true
 	}