Feat: Added GameGimmick interface

The interface will function as a content replacement option in the Strategy principle.

src/main/java/edu/ntnu/idi/idatt2003/g40/mappe/view/widgets/minigames/GameGimmick.java

@@ -0,0 +1,30 @@
+package edu.ntnu.idi.idatt2003.g40.mappe.view.widgets.minigames;
+
+import java.util.function.IntConsumer;
+import javafx.scene.Node;
+
+/**
+ * Strategy interface defining the central
+ * logic and layout for individual minigames.
+ */
+public interface GameGimmick {
+
+  /**
+   * Getter method for JavaFx root element of this gimmick.
+   *
+   * @return This games root as a {@link Node}
+   */
+  Node getCanvasNode();
+
+  /**
+   * Initializes the game behavior, wiring score changes back to the engine.
+   *
+   * @param scoreModifier Callback function to adjust the global score.
+   */
+  void initialize(IntConsumer scoreModifier);
+
+  /**
+   * Called on every frame tick (or second) by the main game loop.
+   */
+  void updateTick();
+}