You need to specify the MAIN and LAUNCHER in the the intent filter for the activity you want to start on launch by :
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
if you want that Splach Activity as your launcher , your manifest must be :
<application>
<activity
android:name="project.shirsho.Menu"
android:label="@string/app_name" >
</activity>
<activity
android:name="project.shirsho.MainActivity"
android:label="@string/app_name" >
</activity>
<activity
android:name="project.shirsho.Splash"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name="project.shirsho.Textplay"
android:label="@string/app_name" >
</activity>
</application>