diff --git a/packages/boop-game/src/game/commands.ts b/packages/boop-game/src/game/commands.ts
index bd848af..89d4e02 100644
--- a/packages/boop-game/src/game/commands.ts
+++ b/packages/boop-game/src/game/commands.ts
@@ -241,7 +241,10 @@ async function turn(game: BoopGame, turnPlayer: PlayerType) {
 }
 const turnCommand = registry.register('turn <player>', turn);
 export const commands = {
-    play: (player: PlayerType, row: number, col: number, type: PieceType) => {
-        return `play ${player} ${row} ${col} ${type}`;
-    }
+    play: (player: PlayerType, row: number, col: number, type?: PieceType) => {
+        if (type) {
+            return `play ${player} ${row} ${col} ${type}`;
+        }
+        return `play ${player} ${row} ${col}`;
+    },
 };
\ No newline at end of file
diff --git a/packages/boop-game/src/scenes/BoardRenderer.ts b/packages/boop-game/src/scenes/BoardRenderer.ts
index e0a34e7..ba06587 100644
--- a/packages/boop-game/src/scenes/BoardRenderer.ts
+++ b/packages/boop-game/src/scenes/BoardRenderer.ts
@@ -111,6 +111,40 @@ export class BoardRenderer {
     }
   }
 
+  /**
+   * 设置棋盘上棋子的点击处理（用于选择要升级的棋子）
+   */
+  setupPieceInput(
+    getState: () => BoopState,
+    onPieceClick: (row: number, col: number) => void,
+    checkWinner: () => boolean
+  ): void {
+    for (let row = 0; row < BOARD_SIZE; row++) {
+      for (let col = 0; col < BOARD_SIZE; col++) {
+        const x = BOARD_OFFSET.x + col * CELL_SIZE + CELL_SIZE / 2;
+        const y = BOARD_OFFSET.y + row * CELL_SIZE + CELL_SIZE / 2;
+
+        const zone = this.scene.add.zone(x, y, CELL_SIZE, CELL_SIZE).setInteractive();
+
+        zone.on('pointerdown', () => {
+          const state = getState();
+          const isOccupied = !!state.regions.board.partMap[`${row},${col}`];
+          if (isOccupied && !checkWinner()) {
+            onPieceClick(row, col);
+          }
+        });
+      }
+    }
+  }
+
+  /**
+   * 更新棋盘上棋子的交互状态
+   */
+  updatePieceInteraction(enabled: boolean): void {
+    // 可以通过此方法启用/禁用棋子点击
+    // 暂时通过重新设置 zone 的 interactive 状态来实现
+  }
+
   destroy(): void {
     this.container.destroy();
     this.gridGraphics.destroy();
diff --git a/packages/boop-game/src/scenes/ErrorOverlay.ts b/packages/boop-game/src/scenes/ErrorOverlay.ts
new file mode 100644
index 0000000..064fca6
--- /dev/null
+++ b/packages/boop-game/src/scenes/ErrorOverlay.ts
@@ -0,0 +1,107 @@
+import Phaser from 'phaser';
+import { BOARD_OFFSET, CELL_SIZE, BOARD_SIZE } from './BoardRenderer';
+
+export class ErrorOverlay {
+  private overlay?: Phaser.GameObjects.Container;
+  private hideTimeout?: Phaser.Time.TimerEvent;
+
+  constructor(private scene: Phaser.Scene) {
+    // 初始时不显示
+  }
+
+  show(message: string, duration: number = 2000): void {
+    // 清除之前的定时器
+    this.hideTimeout?.remove();
+
+    // 销毁之前的 overlay
+    if (this.overlay) {
+      this.overlay.destroy();
+    }
+
+    this.overlay = this.scene.add.container();
+
+    // 半透明背景（可点击关闭）
+    const bg = this.scene.add.rectangle(
+      BOARD_OFFSET.x + (BOARD_SIZE * CELL_SIZE) / 2,
+      BOARD_OFFSET.y + (BOARD_SIZE * CELL_SIZE) / 2,
+      BOARD_SIZE * CELL_SIZE + 200,
+      BOARD_SIZE * CELL_SIZE + 200,
+      0x000000,
+      0.4,
+    ).setInteractive();
+
+    bg.on('pointerdown', () => {
+      this.hide();
+    });
+
+    this.overlay.add(bg);
+
+    // 错误提示框
+    const errorBoxY = BOARD_OFFSET.y + (BOARD_SIZE * CELL_SIZE) / 2 - 60;
+    const errorBox = this.scene.add.container(
+      BOARD_OFFSET.x + (BOARD_SIZE * CELL_SIZE) / 2,
+      errorBoxY
+    );
+
+    // 错误框背景
+    const boxBg = this.scene.add.rectangle(0, 0, 450, 100, 0xef4444, 0.95)
+      .setStrokeStyle(4, 0xdc2626);
+
+    // 错误图标
+    const iconText = this.scene.add.text(-180, 0, '❌', {
+      fontSize: '36px',
+    }).setOrigin(0.5);
+
+    // 错误文本
+    const errorText = this.scene.add.text(30, 0, message, {
+      fontSize: '22px',
+      fontFamily: 'Arial',
+      color: '#ffffff',
+      align: 'center',
+      wordWrap: { width: 380 },
+    }).setOrigin(0, 0.5);
+
+    errorBox.add([boxBg, iconText, errorText]);
+    this.overlay.add(errorBox);
+
+    // 出现动画
+    errorBox.setScale(0);
+    errorBox.setAlpha(0);
+    this.scene.tweens.add({
+      targets: errorBox,
+      scale: 1,
+      alpha: 1,
+      duration: 300,
+      ease: 'Back.easeOut',
+    });
+
+    // 自动隐藏
+    this.hideTimeout = this.scene.time.delayedCall(duration, () => {
+      this.hide();
+    });
+  }
+
+  hide(): void {
+    this.hideTimeout?.remove();
+    this.hideTimeout = undefined;
+
+    if (this.overlay) {
+      const overlay = this.overlay;
+      // 消失动画
+      this.scene.tweens.add({
+        targets: overlay,
+        alpha: 0,
+        duration: 200,
+        onComplete: () => {
+          overlay.destroy();
+          this.overlay = undefined;
+        },
+      });
+    }
+  }
+
+  destroy(): void {
+    this.hideTimeout?.remove();
+    this.overlay?.destroy();
+  }
+}
diff --git a/packages/boop-game/src/scenes/GameScene.ts b/packages/boop-game/src/scenes/GameScene.ts
index 8a55593..71b9f95 100644
--- a/packages/boop-game/src/scenes/GameScene.ts
+++ b/packages/boop-game/src/scenes/GameScene.ts
@@ -7,6 +7,7 @@ import { SupplyUI } from './SupplyUI';
 import { PieceTypeSelector } from './PieceTypeSelector';
 import { WinnerOverlay } from './WinnerOverlay';
 import { StartOverlay } from './StartOverlay';
+import { ErrorOverlay } from './ErrorOverlay';
 
 export class GameScene extends GameHostScene<BoopState> {
   private boardRenderer!: BoardRenderer;
@@ -14,6 +15,7 @@ export class GameScene extends GameHostScene<BoopState> {
   private pieceTypeSelector!: PieceTypeSelector;
   private winnerOverlay!: WinnerOverlay;
   private startOverlay!: StartOverlay;
+  private errorOverlay!: ErrorOverlay;
 
   constructor() {
     super('GameScene');
@@ -28,6 +30,7 @@ export class GameScene extends GameHostScene<BoopState> {
     this.pieceTypeSelector = new PieceTypeSelector(this);
     this.winnerOverlay = new WinnerOverlay(this, () => this.restartGame());
     this.startOverlay = new StartOverlay(this, () => this.startGame());
+    this.errorOverlay = new ErrorOverlay(this);
 
     // 设置棋子生成器
     this.disposables.add(createPieceSpawner(this));
@@ -39,6 +42,13 @@ export class GameScene extends GameHostScene<BoopState> {
       () => this.gameHost.status.value !== 'running' || !!this.state.winner
     );
 
+    // 设置棋子点击处理（用于棋盘满时选择要升级的棋子）
+    this.boardRenderer.setupPieceInput(
+      () => this.state,
+      (row, col) => this.handlePieceClick(row, col),
+      () => this.gameHost.status.value !== 'running' || !!this.state.winner
+    );
+
     // 监听游戏状态变化
     this.addEffect(() => {
       const status = this.gameHost.status.value;
@@ -72,7 +82,16 @@ export class GameScene extends GameHostScene<BoopState> {
     const cmd = commands.play(this.state.currentPlayer, row, col, selectedType);
     const error = this.gameHost.onInput(cmd);
     if (error) {
-      console.warn('Invalid move:', error);
+      this.errorOverlay.show(error);
+    }
+  }
+
+  private handlePieceClick(row: number, col: number): void {
+    // 棋盘满时，点击棋子触发升级
+    const cmd = commands.play(this.state.currentPlayer, row, col);
+    const error = this.gameHost.onInput(cmd);
+    if (error) {
+      this.errorOverlay.show(error);
     }
   }