why does the menu button in the emulator show all the activities of my app?

i just want it to show only one activity on the main menu and hide the remaining ones.

My manifest file looks something like this.

<application android:icon="@drawable/icon" android:label="@string/app_name"
    android:debuggable="true">
    <activity android:name=".MainAct" android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>开发者_StackOverflow社区
    </activity>
    <activity android:name=".StartGame" android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".Instructions" android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".About" android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

You don't need to repeat these lines for all activities;

    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>

Just for the main one

(as an ad-on to your comments question:

From: http://developer.android.com/guide/topics/manifest/manifest-intro.html

The icon and label set for an intent filter are used to represent a component whenever the component is presented to the user as fulfilling the function advertised by the filter. For example, a filter with "android.intent.action.MAIN" and "android.intent.category.LAUNCHER" settings advertises an activity as one that initiates an application — that is, as one that should be displayed in the application launcher. The icon and label set in the filter are therefore the ones displayed in the launcher.

Well, this is just a guess, but you have 2 intent filters in your manifest. If you only want one Activity for your entry point, you should only need the one intent filter for MAIN and LAUNCHER.