diff --git a/app/src/main/java/com/androidtetris/activity/main/MainActivity.kt b/app/src/main/java/com/androidtetris/activity/main/MainActivity.kt
index e58b04f..90432af 100644
--- a/app/src/main/java/com/androidtetris/activity/main/MainActivity.kt
+++ b/app/src/main/java/com/androidtetris/activity/main/MainActivity.kt
@@ -62,7 +62,7 @@ class MainActivity : AppCompatActivity(), OnItemSelectedListener {
 
         // Game level
         val gameLevels: MutableList<String> = mutableListOf(defaultSpinnerSelection)
-        for(i in 1 until 20) { gameLevels.add(i.toString()) }
+        for(i in 1 until 15) { gameLevels.add(i.toString()) }
         // Set the adapter
         setAdapter(gameLevelSpinner, gameLevels)
         val gameLevelSetValue: Int = SettingsHandler.getGameLevel() // Returns 1 by default
@@ -120,7 +120,7 @@ class MainActivity : AppCompatActivity(), OnItemSelectedListener {
     }
 
     override fun onNothingSelected(parent: AdapterView<*>?) {
-        TODO("Not yet implemented")
+        /* Not implemented */
     }
 
     private fun getSpinnerIndex(spinner: Spinner, string: String): Int {
diff --git a/app/src/main/java/com/androidtetris/activity/tetris/GridCanvas.kt b/app/src/main/java/com/androidtetris/activity/tetris/GridCanvas.kt
index 215fe52..69509cc 100644
--- a/app/src/main/java/com/androidtetris/activity/tetris/GridCanvas.kt
+++ b/app/src/main/java/com/androidtetris/activity/tetris/GridCanvas.kt
@@ -309,6 +309,9 @@ class GridCanvas(context: Context, attrs: AttributeSet?) : View(context, attrs)
 
     private fun isGhostCollision(coordinates: List<Point>): Boolean {
         // Checks if there's a collision for every y+1, x of the supplied coordinates, in the grid.
+        // y+1 because if we checked y, that's where the tetromino's lowest y point is, and therefore it
+        // is guaranteed to not be occupied in the grid. If we did this, the bottom-most line of the ghost
+        // would be drawn on the next line.
         // This function is used solely for the ghost piece's hard-dropping.
         for(point in coordinates) {
             val y = point.y+1
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index dd7ffc5..b16fb68 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -6,7 +6,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:theme="@style/Theme.AndroidTetris"
-    tools:context=".MainActivity">
+    tools:context="com.androidtetris.activity.main.MainActivity">
 
     <Button
         android:id="@+id/btn_startgame"
@@ -128,7 +128,6 @@
         android:layout_marginEnd="9dp"
         android:background="@drawable/rounded_layout"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintHorizontal_bias="1.0"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/gridSizeLayout">
 
@@ -154,12 +153,10 @@
             android:layout_marginEnd="123dp"
             android:layout_marginBottom="8dp"
             android:minHeight="48dp"
-            android:dropDownWidth="wrap_content"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toEndOf="@+id/txt_startingHeight"
             app:layout_constraintTop_toTopOf="parent"
-            app:layout_constraintVertical_bias="0.0"
             tools:ignore="SpeakableTextPresentCheck" />
     </androidx.constraintlayout.widget.ConstraintLayout>
 
@@ -196,6 +193,7 @@
             android:layout_marginTop="8dp"
             android:layout_marginEnd="123dp"
             android:layout_marginBottom="8dp"
+            android:dropDownWidth="wrap_content"
             android:minHeight="48dp"
             app:layout_constraintBottom_toBottomOf="parent"
             app:layout_constraintEnd_toEndOf="parent"