diff --git a/data/ObjectCombos_NA.json b/data/ObjectCombos_NA.json
index b1770c9..0f2d814 100644
--- a/data/ObjectCombos_NA.json
+++ b/data/ObjectCombos_NA.json
@@ -52,12 +52,6 @@
       "ModelAddress": "0x00000000",
       "Behavior": "0x13000494"
     },
-    {
-      "Name": "Aquarium Bubble",
-      "ModelID": "0x00",
-      "ModelAddress": "0x00000000",
-      "Behavior": "0x13000494"
-    },
     {
       "Name": "Arrow Lift",
       "ModelID": "0x37",
@@ -70,12 +64,6 @@
       "ModelAddress": "0x0C000104",
       "Behavior": "0x130020E8"
     },
-    {
-      "Name": "Baby Penguin",
-      "ModelID": "0x57",
-      "ModelAddress": "0x0C000104",
-      "Behavior": "0x130020E8"
-    },
     {
       "Name": "Bascule Bridge",
       "ModelID": "0x38",
@@ -118,30 +106,12 @@
       "ModelAddress": "0x0E0003A0",
       "Behavior": "0x13004D64"
     },
-    {
-      "Name": "Big Rotating Gear",
-      "ModelID": "0x44",
-      "ModelAddress": "0x0E0003A0",
-      "Behavior": "0x13004D64"
-    },
     {
       "Name": "Big Staircase Level Part",
       "ModelID": "0x04",
       "ModelAddress": "0x0E000820",
       "Behavior": "0x13002A48"
     },
-    {
-      "Name": "Big Staircase Level Part",
-      "ModelID": "0x04",
-      "ModelAddress": "0x0E000820",
-      "Behavior": "0x13002A48"
-    },
-    {
-      "Name": "Bird ambient sounds",
-      "ModelID": "0x00",
-      "ModelAddress": "0x00000000",
-      "Behavior": "0x13003C7C"
-    },
     {
       "Name": "Bird ambient sounds",
       "ModelID": "0x00",
@@ -160,30 +130,12 @@
       "ModelAddress": "0x16000200",
       "Behavior": "0x13002588"
     },
-    {
-      "Name": "Blue Coin",
-      "ModelID": "0x76",
-      "ModelAddress": "0x16000200",
-      "Behavior": "0x13002588"
-    },
     {
       "Name": "Blue Coins Switch",
       "ModelID": "0x8C",
       "ModelAddress": "0x0F000000",
       "Behavior": "0x13002568"
     },
-    {
-      "Name": "Blue Coins Switch",
-      "ModelID": "0x8C",
-      "ModelAddress": "0x0F000000",
-      "Behavior": "0x13002568"
-    },
-    {
-      "Name": "Blue Elevator Platform",
-      "ModelID": "0x40",
-      "ModelAddress": "0x0E0008F0",
-      "Behavior": "0x13000CFC"
-    },
     {
       "Name": "Blue Elevator Platform",
       "ModelID": "0x40",
@@ -196,12 +148,6 @@
       "ModelAddress": "0x16000B8C",
       "Behavior": "0x13000C84"
     },
-    {
-      "Name": "Blue Flame",
-      "ModelID": "0x91",
-      "ModelAddress": "0x16000B8C",
-      "Behavior": "0x13000C84"
-    },
     {
       "Name": "Blue Smiley",
       "ModelID": "0x37",
@@ -232,12 +178,6 @@
       "ModelAddress": "0x0C000224",
       "Behavior": "0x13002790"
     },
-    {
-      "Name": "Boo Buddy",
-      "ModelID": "0x54",
-      "ModelAddress": "0x0C000224",
-      "Behavior": "0x130027D0"
-    },
     {
       "Name": "Boo Buddy 2",
       "ModelID": "0x54",
@@ -686,7 +626,10 @@
       "Name": "Coin Formation",
       "ModelID": "0x00",
       "ModelAddress": "0x00000000",
-      "Behavior": "0x130008EC"
+      "Behavior": "0x130008EC",
+      "BP2_NAME": "Content",
+      "BP2_DESCRIPTION": "0: Five coins horizontal\n2: Coin ring horizontal\n4: Coin arrow\n16: Five coins horizontal flying\n17: Five coins vertical\n18: Coin ring horizontal flying\n19: Coin ring vertical"
+    
     },
     {
       "Name": "Coins",
@@ -2639,7 +2582,7 @@
       "Behavior": "0x13002F60"
     },
     {
-      "Name": "Warp",
+      "Name": "Warp (for level exit)",
       "ModelID": "0x00",
       "ModelAddress": "0x00000000",
       "Behavior": "0x13002F84"
@@ -2925,6 +2868,152 @@
       "ModelID": "0x55",
       "ModelAddress": "0x0C000468",
       "Behavior": "0x13004538"
+    },
+    {
+      "Name": "Beta Blarrg [MOP1]",
+      "ModelID": "0x54",
+      "ModelAddress": "0x0C000224",
+      "Behavior": "0x130023D0"
+    },
+    {
+      "Name": "Trampoline [MOP1]",
+      "ModelID": "0xB5",
+      "ModelAddress": "0x0C000000",
+      "Behavior": "0x13001608"
+    },
+    {
+      "Name": "Noteblock [MOP1]",
+      "ModelID": "0x7B",
+      "ModelAddress": "0x0301dbf8",
+      "Behavior": "0x13000174"
+    },
+    {
+      "Name": "Sandblock [MOP1]",
+      "ModelID": "0x99",
+      "ModelAddress": "0x030225e4",
+      "Behavior": "0x1300064C"
+    },
+    {
+      "Name": "Shrinkplatform [MOP1]",
+      "ModelID": "0x98",
+      "ModelAddress": "0x030212f4",
+      "Behavior": "0x13000624"
+    },
+    {
+      "Name": "Spring [MOP1]",
+      "ModelID": "0x92",
+      "ModelAddress": "0x0301fc98",
+      "Behavior": "0x130005B4"
+    },
+    {
+      "Name": "Shell 1 [MOP1]",
+      "ModelID": "0x9B",
+      "ModelAddress": "0x0f000adc",
+      "Behavior": "0x13004218"
+    },
+    {
+      "Name": "Shell 2 [MOP1]",
+      "ModelID": "0x9D",
+      "ModelAddress": "0x0f000b08",
+      "Behavior": "0x13004218"
+    },
+    {
+      "Name": "Emitter [MOP2]",
+      "ModelID": "0x00",
+      "ModelAddress": "0x00000000",
+      "Behavior": "0x130050B4",
+      "BP1_NAME": "Param 1",
+      "BP2_NAME": "Param 2",
+      "BP1_DESCRIPTION": "Spawn radius, Red - value",
+      "BP2_DESCRIPTION": "Green - value, Blue - value"
+    },
+    {
+      "Name": "Flipclock [MOP2]",
+      "ModelID": "0xF0",
+      "ModelAddress": "0x0302272c",
+      "Behavior": "0x130050D0"
+    },
+    {
+      "Name": "Jukebox [MOP2]",
+      "ModelID": "0x00",
+      "ModelAddress": "0x00000000",
+      "Behavior": "0x13005104",
+      "BP1_NAME": "First",
+      "BP2_NAME": "Last",
+      "BP1_DESCRIPTION": "First song in list",
+      "BP2_DESCRIPTION": "Last song in list"
+    },
+    {
+      "Name": "PSwitch [MOP2]",
+      "ModelID": "0xCF",
+      "ModelAddress": "0x0f0004cc",
+      "Behavior": "0x1300512C"
+    },
+    {
+      "Name": "Switch for Switchblocks [MOP2]",
+      "ModelID": "0xF2",
+      "ModelAddress": "0x03022708",
+      "Behavior": "0x13003AE0",
+      "BP2_NAME": "Color",
+      "BP2_DESCRIPTION": "0 for red\n1 for blue"
+    },
+    {
+      "Name": "Switchblock [MOP2]",
+      "ModelID": "0xF1",
+      "ModelAddress": "0x030226d4",
+      "Behavior": "0x13004EA0",
+      "BP2_NAME": "Color",
+      "BP2_DESCRIPTION": "0 for red\n2 for blue",
+      "BP1_NAME": "Start Color",
+      "BP1_DESCRIPTION": "0 to start red\n2 to start blue"
+    },
+    {
+      "Name": "Checkpoint Flag [MOP3]",
+      "ModelID": "0x2E",
+      "ModelAddress": "0x00606660",
+      "Behavior": "0x13000D50",
+      "BP2_NAME": "Flag",
+      "BP2_DESCRIPTION": "0 for regular flag\n1 for reset flag"
+    },
+    {
+      "Name": "Moving & Rotating Block [MOP3]",
+      "ModelID": "0x2D",
+      "ModelAddress": "0x00603670",
+      "Behavior": "0x13000D24",
+      "BP1_NAME": "Color",
+      "BP1_DESCRIPTION": "0 for blue\n1 for red",
+      "BP2_NAME": "PathID",
+      "BP2_DESCRIPTION": "Path ID (0, 1 and 2 are predefined)"
+    },
+    {
+      "Name": "Flipswitch Panel [MOP3]",
+      "ModelID": "0x2A",
+      "ModelAddress": "0x005f9fe0",
+      "Behavior": "0x130005D8"
+    },
+    {
+      "Name": "Flipswitch Panel Starspawner [MOP3]",
+      "ModelID": "0x00",
+      "ModelAddress": "0x00000000",
+      "Behavior": "0x130002A0",
+      "BP1_NAME": "Star #",
+      "BP1_DESCRIPTION": "Star number"
+    },
+    {
+      "Name": "Green Switchboard [MOP3]",
+      "ModelID": "0x2B",
+      "ModelAddress": "0x005fd8b0",
+      "Behavior": "0x13000CFC",
+      "BP1_NAME": "Direct 1",
+      "BP1_DESCRIPTION": "Maximum distance into direction1",
+      "BP2_NAME": "Direct 2",
+      "BP2_DESCRIPTION": "Maximum distance into direction2"
+    },
+    {
+      "Name": "Flipswap Platform [MOP3]",
+      "ModelID": "0x2F",
+      "ModelAddress": "0x005f9ac0",
+      "Behavior": "0x13000278"
     }
   ]
 }
\ No newline at end of file
diff --git a/src/Forms/MainForm.cs b/src/Forms/MainForm.cs
index b77c3da..be49bd7 100644
--- a/src/Forms/MainForm.cs
+++ b/src/Forms/MainForm.cs
@@ -508,7 +508,7 @@ private void saveROMAsToolStripMenuItem_Click(object sender, EventArgs e)
 
         private void saveROMToolStripMenuItem_Click(object sender, EventArgs e)
         {
-            ROM.Instance.saveFileAs(ROM.Instance.Filepath, ROM.Instance.Endian);
+            ROM.Instance.saveFile();
         }
         
         private void settingsToolStripMenuItem_Click(object sender, EventArgs e)
@@ -534,6 +534,14 @@ private void replaceObject(int index, ref SelectComboPreset comboWindow)
             area.Objects[index].setBehaviorFromAddress(comboWindow.ReturnObjectCombo.Behavior);
             treeView1.Nodes[0].Nodes[index].Text = area.Objects[index].getObjectComboName();
             area.Objects[index].SetBehaviorParametersToZero();
+            area.Objects[index].Act1 = true;
+            area.Objects[index].Act2 = true;
+            area.Objects[index].Act3 = true;
+            area.Objects[index].Act4 = true;
+            area.Objects[index].Act5 = true;
+            area.Objects[index].Act6 = false;
+            area.Objects[index].AllActs = true;
+            area.Objects[index].ShowHideActs(true);
             area.Objects[index].UpdateProperties();
         }
 
@@ -680,6 +688,8 @@ private void objectComboPresetToolStripMenuItem_Click(object sender, EventArgs e
             glControl1.Invalidate();
             propertyGrid1.Refresh();
             glControl1.Update(); // Needed after calling propertyGrid1.Refresh();
+            updateSelectedObjectsInROM();
+            Globals.needToSave = true;
         }
 
         private void Form1_Shown(object sender, EventArgs e)
@@ -1069,7 +1079,19 @@ private void propertyGrid1_PropertyValueChanged(object s, PropertyValueChangedEv
                     if (obj == null) return;
                     if (label.Equals("All Acts"))
                     {
-                        obj.ShowHideActs((bool)e.ChangedItem.Value);
+                        bool isAllActs = (bool)e.ChangedItem.Value;
+                        obj.ShowHideActs(isAllActs);
+
+                        if (isAllActs)
+                        {
+                            obj.Act1 = true;
+                            obj.Act2 = true;
+                            obj.Act3 = true;
+                            obj.Act4 = true;
+                            obj.Act5 = true;
+                            obj.Act6 = false;
+                        }
+
                         propertyGrid1.Refresh();
                     }
                     else if (label.Equals("Behavior") || label.Equals("Model ID"))
@@ -1111,7 +1133,24 @@ private void propertyGrid1_PropertyValueChanged(object s, PropertyValueChangedEv
                         if (e.ChangedItem.Label.Equals("Behavior"))
                             if (!obj.canEditBehavior)
                                 continue;
-                        
+
+                        if (e.ChangedItem.Label.Equals("All Acts"))
+                        {
+                            bool isAllActs = (bool)e.ChangedItem.Value;
+                            obj.ShowHideActs(isAllActs);
+
+                            if (isAllActs)
+                            {
+                                obj.Act1 = true;
+                                obj.Act2 = true;
+                                obj.Act3 = true;
+                                obj.Act4 = true;
+                                obj.Act5 = true;
+                                obj.Act6 = false;
+                            }
+
+                            propertyGrid1.Refresh();
+                        }
                         obj.updateROMData();
                     }
                 }
diff --git a/src/ROM.cs b/src/ROM.cs
index 757ab7d..7a012d5 100644
--- a/src/ROM.cs
+++ b/src/ROM.cs
@@ -42,6 +42,7 @@ class ROM
         public string filepath = "";
         public string Filepath { get { return filepath; } }
         private byte[] bytes;
+        private byte[] writeMask;
         private uint[] segStart = new uint[0x20];
         private bool[] segIsMIO0 = new bool[0x20];
         private byte[][] segData = new byte[0x20][];
@@ -134,6 +135,10 @@ private void swapMixedBig()
                 byte temp = bytes[i];
                 bytes[i] = bytes[i + 1];
                 bytes[i + 1] = temp;
+
+                temp = writeMask[i];
+                writeMask[i] = writeMask[i + 1];
+                writeMask[i + 1] = temp;
             }
         }
 
@@ -150,6 +155,15 @@ private void swapLittleBig()
                 bytes[i + 1] = temp[2];
                 bytes[i + 2] = temp[1];
                 bytes[i + 3] = temp[0];
+
+                temp[0] = writeMask[i + 0];
+                temp[1] = writeMask[i + 1];
+                temp[2] = writeMask[i + 2];
+                temp[3] = writeMask[i + 3];
+                writeMask[i + 0] = temp[3];
+                writeMask[i + 1] = temp[2];
+                writeMask[i + 2] = temp[1];
+                writeMask[i + 3] = temp[0];
             }
         }
 
@@ -211,10 +225,26 @@ public string getInternalName()
             return System.Text.Encoding.Default.GetString(getSubArray_safe(Bytes, 0x20, 20));
         }
 
+        public void WriteToFileEx()
+        {
+            FileStream stream = File.OpenWrite(filepath);
+            for (int i = 0; i < bytes.Length; i++)
+            {
+                if (writeMask[i] != 0)
+                {
+                    writeMask[i] = 0;
+                    stream.Seek(i, SeekOrigin.Begin);
+                    stream.WriteByte(bytes[i]);
+                }
+            }
+            stream.Close();
+        }
+
         public void readFile(string filename)
         {
             filepath = filename;
             bytes = File.ReadAllBytes(filename);
+            writeMask = new byte[bytes.Length];
             checkROM();
             Globals.pathToAutoLoadROM = filepath;
             Globals.needToSave = false;
@@ -226,18 +256,18 @@ public void saveFile()
             if (Endian == ROM_Endian.MIXED)
             {
                 swapMixedBig();
-                File.WriteAllBytes(filepath, bytes);
+                WriteToFileEx();
                 swapMixedBig();
             }
             else if (Endian == ROM_Endian.LITTLE)
             {
                 swapLittleBig();
-                File.WriteAllBytes(filepath, bytes);
+                WriteToFileEx();
                 swapLittleBig();
             }
             else // Save as big endian by default
             {
-                File.WriteAllBytes(filepath, bytes);
+                WriteToFileEx();
             }
             Globals.pathToAutoLoadROM = filepath;
             Globals.needToSave = false;
@@ -458,13 +488,21 @@ private int SearchBytes(byte[] haystack, byte[] needle)
             return -1;
         }
 
+        private void addToWriteMask(uint start, int length)
+        {
+            for (int i = 0; i < length; i++)
+                writeMask[i + start] = 1;
+        }
+
         public void writeByteArray(uint offset, byte[] arr)
         {
+            addToWriteMask(offset, arr.Length);
             Array.Copy(arr, 0, bytes, offset, arr.Length);
         }
 
         public void writeByteArray(uint offset, byte[] arr, int arr_offset, int arr_length)
         {
+            addToWriteMask(offset, arr.Length);
             Array.Copy(arr, arr_offset, bytes, offset, arr_length);
         }
 
@@ -477,6 +515,7 @@ public void writeByteArrayToSegment(uint segAddr, byte[] arr)
 
         public void writeWord(uint offset, int word)
         {
+            addToWriteMask(offset, 4);
             bytes[offset + 0] = (byte)(word >> 24);
             bytes[offset + 1] = (byte)(word >> 16);
             bytes[offset + 2] = (byte)(word >> 8);
@@ -490,6 +529,7 @@ public void writeWord(uint offset, uint word)
 
         public void writeHalfword(uint offset, short half)
         {
+            addToWriteMask(offset, 2);
             bytes[offset + 0] = (byte)(half >> 8);
             bytes[offset + 1] = (byte)(half);
         }
@@ -501,6 +541,7 @@ public void writeHalfword(uint offset, ushort word)
 
         public void writeByte(uint offset, byte b)
         {
+            addToWriteMask(offset, 1);
             bytes[offset] = b;
         }
 
@@ -631,37 +672,37 @@ public void findAndSetSegment02()
 
         public Dictionary<string, ushort> levelIDs = new Dictionary<string, ushort>
         {
-            { "Big Boo's Haunt", 0x04 },
-            { "Cool Cool Mountain", 0x05 },
-            { "Inside Castle", 0x06 },
-            { "Hazy Maze Cave", 0x07 },
-            { "Shifting Sand Land", 0x08 },
-            { "Bob-omb Battlefield", 0x09 },
-            { "Snowman's Land", 0x0A },
-            { "Wet Dry World", 0x0B },
-            { "Jolly Roger Bay", 0x0C },
-            { "Tiny Huge Island", 0x0D },
-            { "Tick Tock Clock", 0x0E },
-            { "Rainbow Ride", 0x0F },
-            { "Castle Grounds", 0x10 },
-            { "Bowser Course 1", 0x11 },
-            { "Vanish Cap", 0x12 },
-            { "Bowser Course 2", 0x13 },
-            { "Secret Aquarium", 0x14 },
-            { "Bowser Course 3", 0x15 },
-            { "Lethal Lava Land", 0x16 },
-            { "Dire Dire Docks", 0x17 },
-            { "Whomp's Fortress", 0x18 },
-            { "End Cake Picture", 0x19 },
-            { "Castle Courtyard", 0x1A },
-            { "Peach's Secret Slide", 0x1B },
-            { "Metal Cap", 0x1C },
-            { "Wing Cap", 0x1D },
-            { "Bowser Battle 1", 0x1E },
-            { "Rainbow Clouds", 0x1F },
-            { "Bowser Battle 2", 0x21 },
-            { "Bowser Battle 3", 0x22 },
-            { "Tall Tall Mountain", 0x24 }
+            { "[C01] Bob-omb Battlefield", 0x09 },
+            { "[C02] Whomp's Fortress", 0x18 },
+            { "[C03] Jolly Roger Bay", 0x0C },
+            { "[C04] Cool Cool Mountain", 0x05 },
+            { "[C05] Big Boo's Haunt", 0x04 },
+            { "[C06] Hazy Maze Cave", 0x07 },
+            { "[C07] Lethal Lava Land", 0x16 },
+            { "[C08] Shifting Sand Land", 0x08 },
+            { "[C09] Dire Dire Docks", 0x17 },
+            { "[C10] Snowman's Land", 0x0A },
+            { "[C11] Wet Dry World", 0x0B },
+            { "[C12] Tall Tall Mountain", 0x24 },
+            { "[C13] Tiny Huge Island", 0x0D },
+            { "[C14] Tick Tock Clock", 0x0E },
+            { "[C15] Rainbow Ride", 0x0F },
+            { "[OW1] Castle Grounds", 0x10 },
+            { "[OW2] Inside Castle", 0x06 },
+            { "[OW3] Castle Courtyard", 0x1A },
+            { "[BC1] Bowser Course 1", 0x11 },
+            { "[BC2] Bowser Course 2", 0x13 },
+            { "[BC3] Bowser Course 3", 0x15 },
+            { "[MCL] Metal Cap", 0x1C },
+            { "[WCL] Wing Cap", 0x1D },
+            { "[VCL] Vanish Cap", 0x12 },
+            { "[BB1] Bowser Battle 1", 0x1E },
+            { "[BB2] Bowser Battle 2", 0x21 },
+            { "[BB3] Bowser Battle 3", 0x22 },
+            { "[SC1] Secret Aquarium", 0x14 },
+            { "[SC2] Rainbow Clouds", 0x1F },
+            { "[SC3] End Cake Picture", 0x19 },
+            { "[SlC] Peach's Secret Slide", 0x1B }
         };
         
     }