Removed the MainActivity page top bar, added sprite images, added app logo to...

        <!--Locks the orientation of main activity to only allow portrait mode-->

        <activity

            android:name=".GameActivity"

            android:theme="@style/Theme.Design.NoActionBar"

            android:theme="@style/Theme.AppCompat.NoActionBar"

            android:configChanges="orientation"

            android:screenOrientation="portrait"/>

        <activity

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        // the if statement below hides the action bar

        // https://www.geeksforgeeks.org/different-ways-to-hide-action-bar-in-android-with-examples/

        if (getSupportActionBar() != null) {

            getSupportActionBar().hide();

        }

        // initalizes 8-bit Invaders Logo

        ImageView myImageView = (ImageView) findViewById(R.id.image_logo);

        myImageView.setImageResource(R.drawable.logobit);

        // Creates new Intent and starts GameActivity if 'play' is pressed on MainActivity screen.

        findViewById(R.id.play_button).setOnClickListener(new View.OnClickListener() {

            @Override