diff --git a/src/config.c b/src/config.c
index 9ec8b272a..5d870d8cd 100644
--- a/src/config.c
+++ b/src/config.c
@@ -37,6 +37,8 @@
 
 T1MConfigStruct T1MConfig = { 0 };
 
+static const char *T1MGlobalSettingsPath = "cfg/Tomb1Main.json5";
+
 static int8_t ReadBarShowingMode(
     struct json_object_s *obj, const char *name, int8_t default_value)
 {
diff --git a/src/config.h b/src/config.h
index 531b9c58b..b921cdcd1 100644
--- a/src/config.h
+++ b/src/config.h
@@ -86,6 +86,11 @@ typedef struct {
         uint32_t fps_counter : 1;
     } render_flags;
 
+    struct {
+        double text_scale;
+        double bar_scale;
+    } ui;
+
     int32_t sound_volume;
     int32_t music_volume;
 } T1MConfigStruct;
diff --git a/src/game/demo.c b/src/game/demo.c
index 4d3e71b4c..566e09fef 100644
--- a/src/game/demo.c
+++ b/src/game/demo.c
@@ -13,6 +13,8 @@
 
 #include <stdbool.h>
 
+static int32_t DemoLevel = -1;
+
 int32_t StartDemo()
 {
     TEXTSTRING *txt;
diff --git a/src/game/draw.c b/src/game/draw.c
index e3d2b79cf..15de3a310 100644
--- a/src/game/draw.c
+++ b/src/game/draw.c
@@ -19,6 +19,7 @@ static PHD_MATRIX *IMMatrixPtr = NULL;
 static PHD_MATRIX IMMatrixStack[MAX_NESTED_MATRICES] = { 0 };
 static int32_t IMRate = 0;
 static int32_t IMFrac = 0;
+static bool CameraUnderwater = false;
 
 int32_t DrawPhaseCinematic()
 {
diff --git a/src/game/inventry.c b/src/game/inventry.c
index 0c623979c..d51947355 100644
--- a/src/game/inventry.c
+++ b/src/game/inventry.c
@@ -54,7 +54,7 @@ int32_t Display_Inventory(int inv_mode)
     int32_t pass_mode_open = 0;
     if (AmmoText) {
         T_RemovePrint(AmmoText);
-        AmmoText = 0;
+        AmmoText = NULL;
     }
 
     AlterFOV(T1MConfig.fov_value * PHD_DEGREE);
@@ -126,7 +126,7 @@ int32_t Display_Inventory(int inv_mode)
                 if (IDCount) {
                     IDCount--;
                 } else {
-                    IDelay = 0;
+                    IDelay = false;
                 }
             }
             Inv_RingDoMotions(&ring);
diff --git a/src/game/lot.c b/src/game/lot.c
index e97d4778b..92abb46fb 100644
--- a/src/game/lot.c
+++ b/src/game/lot.c
@@ -6,6 +6,9 @@
 
 #include <stddef.h>
 
+static int32_t SlotsUsed = 0;
+static CREATURE_INFO *BaddieSlots = NULL;
+
 void InitialiseLOTArray()
 {
     BaddieSlots =
diff --git a/src/game/option.c b/src/game/option.c
index 9c0a7623c..009d68e88 100644
--- a/src/game/option.c
+++ b/src/game/option.c
@@ -74,6 +74,10 @@ typedef struct TEXT_COLUMN_PLACEMENT {
     int col_num;
 } TEXT_COLUMN_PLACEMENT;
 
+static int32_t PassportMode = 0;
+static int32_t KeyMode = 0;
+static int32_t KeyChange = 0;
+
 static TEXTSTRING *PassportText = NULL;
 static TEXTSTRING *DetailTextHW[DETAIL_HW_NUMBER_OF] = { 0 };
 static TEXTSTRING *SoundText[4] = { 0 };
@@ -140,9 +144,6 @@ static const TEXT_COLUMN_PLACEMENT CtrlTextPlacementCheats[] = {
     { -1, -1 },
 };
 
-static int32_t PassportMode = 0;
-static int32_t KeyMode = 0;
-
 static char NewGameStrings[MAX_GAME_MODES][MAX_GAME_MODE_LENGTH] = { 0 };
 REQUEST_INFO NewGameRequester = {
     MAX_GAME_MODES, // items
@@ -669,11 +670,15 @@ void DoDetailOption(INVENTORY_ITEM *inv_item)
         DetailTextHW[DETAIL_HW_BILINEAR] = T_Print(0, y, buf);
         y += DETAIL_HW_ROW_HEIGHT;
 
-        sprintf(buf, GF.strings[GS_DETAIL_UI_TEXT_SCALE_FMT], UITextScale);
+        sprintf(
+            buf, GF.strings[GS_DETAIL_UI_TEXT_SCALE_FMT],
+            T1MConfig.ui.text_scale);
         DetailTextHW[DETAIL_HW_UI_TEXT_SCALE] = T_Print(0, y, buf);
         y += DETAIL_HW_ROW_HEIGHT;
 
-        sprintf(buf, GF.strings[GS_DETAIL_UI_BAR_SCALE_FMT], UIBarScale);
+        sprintf(
+            buf, GF.strings[GS_DETAIL_UI_BAR_SCALE_FMT],
+            T1MConfig.ui.bar_scale);
         DetailTextHW[DETAIL_HW_UI_BAR_SCALE] = T_Print(0, y, buf);
         y += DETAIL_HW_ROW_HEIGHT;
 
@@ -747,15 +752,15 @@ void DoDetailOption(INVENTORY_ITEM *inv_item)
             break;
 
         case DETAIL_HW_UI_TEXT_SCALE:
-            if (UITextScale < MAX_UI_SCALE) {
-                UITextScale += 0.1;
+            if (T1MConfig.ui.text_scale < MAX_UI_SCALE) {
+                T1MConfig.ui.text_scale += 0.1;
                 reset = 1;
             }
             break;
 
         case DETAIL_HW_UI_BAR_SCALE:
-            if (UIBarScale < MAX_UI_SCALE) {
-                UIBarScale += 0.1;
+            if (T1MConfig.ui.bar_scale < MAX_UI_SCALE) {
+                T1MConfig.ui.bar_scale += 0.1;
                 reset = 1;
             }
             break;
@@ -785,15 +790,15 @@ void DoDetailOption(INVENTORY_ITEM *inv_item)
             break;
 
         case DETAIL_HW_UI_TEXT_SCALE:
-            if (UITextScale > MIN_UI_SCALE) {
-                UITextScale -= 0.1;
+            if (T1MConfig.ui.text_scale > MIN_UI_SCALE) {
+                T1MConfig.ui.text_scale -= 0.1;
                 reset = 1;
             }
             break;
 
         case DETAIL_HW_UI_BAR_SCALE:
-            if (UIBarScale > MIN_UI_SCALE) {
-                UIBarScale -= 0.1;
+            if (T1MConfig.ui.bar_scale > MIN_UI_SCALE) {
+                T1MConfig.ui.bar_scale -= 0.1;
                 reset = 1;
             }
             break;
@@ -871,14 +876,14 @@ void DoSoundOption(INVENTORY_ITEM *inv_item)
     case SOUND_MUSIC_VOLUME:
         if (Input.left && T1MConfig.music_volume > 0) {
             T1MConfig.music_volume--;
-            IDelay = 1;
+            IDelay = true;
             IDCount = 10;
             sprintf(buf, "| %2d", T1MConfig.music_volume);
             T_ChangeText(SoundText[SOUND_MUSIC_VOLUME], buf);
             S_WriteUserSettings();
         } else if (Input.right && T1MConfig.music_volume < 10) {
             T1MConfig.music_volume++;
-            IDelay = 1;
+            IDelay = true;
             IDCount = 10;
             sprintf(buf, "| %2d", T1MConfig.music_volume);
             T_ChangeText(SoundText[SOUND_MUSIC_VOLUME], buf);
@@ -898,14 +903,14 @@ void DoSoundOption(INVENTORY_ITEM *inv_item)
     case SOUND_SOUND_VOLUME:
         if (Input.left && T1MConfig.sound_volume > 0) {
             T1MConfig.sound_volume--;
-            IDelay = 1;
+            IDelay = true;
             IDCount = 10;
             sprintf(buf, "} %2d", T1MConfig.sound_volume);
             T_ChangeText(SoundText[SOUND_SOUND_VOLUME], buf);
             S_WriteUserSettings();
         } else if (Input.right && T1MConfig.sound_volume < 10) {
             T1MConfig.sound_volume++;
-            IDelay = 1;
+            IDelay = true;
             IDCount = 10;
             sprintf(buf, "} %2d", T1MConfig.sound_volume);
             T_ChangeText(SoundText[SOUND_SOUND_VOLUME], buf);
diff --git a/src/game/settings.c b/src/game/settings.c
index 77f02ee15..8c3ccded5 100644
--- a/src/game/settings.c
+++ b/src/game/settings.c
@@ -17,6 +17,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+static const char *ATIUserSettingsPath = "atiset.dat";
+static const char *T1MUserSettingsPath = "cfg/Tomb1Main_runtime.json5";
+
 static int32_t S_ReadUserSettingsATI();
 static int32_t S_ReadUserSettingsT1M();
 static int32_t S_ReadUserSettingsT1MFromJson(const char *cfg_data);
@@ -56,8 +59,8 @@ static int32_t S_ReadUserSettingsATI()
 
     FileRead(&T1MConfig.input.layout, sizeof(int32_t), 1, fp);
 
-    UITextScale = DEFAULT_UI_SCALE;
-    UIBarScale = DEFAULT_UI_SCALE;
+    T1MConfig.ui.text_scale = DEFAULT_UI_SCALE;
+    T1MConfig.ui.bar_scale = DEFAULT_UI_SCALE;
 
     FileClose(fp);
     return 1;
@@ -109,13 +112,13 @@ static int32_t S_ReadUserSettingsT1MFromJson(const char *cfg_data)
         json_object_get_number_int(root_obj, "layout_num", 0);
     CLAMP(T1MConfig.input.layout, 0, 1);
 
-    UITextScale = json_object_get_number_double(
+    T1MConfig.ui.text_scale = json_object_get_number_double(
         root_obj, "ui_text_scale", DEFAULT_UI_SCALE);
-    CLAMP(UITextScale, MIN_UI_SCALE, MAX_UI_SCALE);
+    CLAMP(T1MConfig.ui.text_scale, MIN_UI_SCALE, MAX_UI_SCALE);
 
-    UIBarScale = json_object_get_number_double(
+    T1MConfig.ui.bar_scale = json_object_get_number_double(
         root_obj, "ui_bar_scale", DEFAULT_UI_SCALE);
-    CLAMP(UIBarScale, MIN_UI_SCALE, MAX_UI_SCALE);
+    CLAMP(T1MConfig.ui.bar_scale, MIN_UI_SCALE, MAX_UI_SCALE);
 
     struct json_array_s *layout_arr = json_object_get_array(root_obj, "layout");
     for (int i = 0; i < KEY_NUMBER_OF; i++) {
@@ -188,8 +191,10 @@ static int32_t S_WriteUserSettingsT1M()
         root_obj, "sound_volume", T1MConfig.sound_volume);
     json_object_append_number_int(
         root_obj, "layout_num", T1MConfig.input.layout);
-    json_object_append_number_double(root_obj, "ui_text_scale", UITextScale);
-    json_object_append_number_double(root_obj, "ui_bar_scale", UIBarScale);
+    json_object_append_number_double(
+        root_obj, "ui_text_scale", T1MConfig.ui.text_scale);
+    json_object_append_number_double(
+        root_obj, "ui_bar_scale", T1MConfig.ui.bar_scale);
 
     struct json_array_s *layout_arr = json_array_new();
     for (int i = 0; i < KEY_NUMBER_OF; i++) {
diff --git a/src/global/vars.c b/src/global/vars.c
index 635a3eaf8..ec11014b1 100644
--- a/src/global/vars.c
+++ b/src/global/vars.c
@@ -15,16 +15,7 @@
 #include "game/effects/turn_180.h"
 #include "global/vars.h"
 
-const char *ATIUserSettingsPath = "atiset.dat";
-const char *T1MUserSettingsPath = "cfg/Tomb1Main_runtime.json5";
-const char *T1MGlobalSettingsPath = "cfg/Tomb1Main.json5";
-const char *T1MGameflowPath = "cfg/Tomb1Main_gameflow.json5";
-const char *T1MGameflowGoldPath = "cfg/Tomb1Main_gameflow_ub.json5";
-
 char *GameMemoryPointer = NULL;
-int8_t IsGameWindowActive = 1;
-double UITextScale = 1.0;
-double UIBarScale = 1.0;
 TEXTSTRING *AmmoText = NULL;
 TEXTSTRING *FPSText = NULL;
 int32_t FPSCounter = 0;
@@ -39,20 +30,17 @@ void (*EffectRoutines[])(ITEM_INFO *item) = {
 bool SoundIsActive = true;
 int16_t SampleLUT[MAX_SAMPLES] = { 0 };
 SAMPLE_INFO *SampleInfos = NULL;
-SAMPLE_DATA **SampleData = NULL;
 int32_t NumSampleData = 0;
 int16_t MusicTrack = 0;
-int16_t MusicTrackLooped = 0;
 bool MusicLoop = false;
 uint16_t MusicTrackFlags[MAX_CD_TRACKS] = { 0 };
 int32_t MnSoundMasterVolume = 32;
 
 int32_t NoInputCount = 0;
-int32_t IDelay = 0;
+bool IDelay = false;
 int32_t IDCount = 0;
 INPUT_STATE Input = { 0 };
 INPUT_STATE InputDB = { 0 };
-int32_t KeyChange = 0;
 int32_t OptionSelected = 0;
 
 int32_t PhdWinMaxX = 0;
@@ -87,12 +75,10 @@ GAMEFLOW GF = { 0 };
 LARA_INFO Lara = { 0 };
 ITEM_INFO *LaraItem = NULL;
 CAMERA_INFO Camera = { 0 };
-bool CameraUnderwater = false;
 SAVEGAME_INFO SaveGame = { 0 };
 int32_t SavedGamesCount = 0;
 int32_t SaveCounter = 0;
 int32_t CurrentLevel = -1;
-int32_t DemoLevel = -1;
 uint32_t *DemoPtr = NULL;
 int32_t DemoCount = 0;
 int32_t LevelComplete = 0;
@@ -125,8 +111,6 @@ uint16_t *Overlap = NULL;
 int16_t *GroundZone[2] = { NULL };
 int16_t *GroundZone2[2] = { NULL };
 int16_t *FlyZone[2] = { NULL };
-int32_t SlotsUsed = 0;
-CREATURE_INFO *BaddieSlots = NULL;
 ANIM_STRUCT *Anims = NULL;
 ANIM_CHANGE_STRUCT *AnimChanges = NULL;
 ANIM_RANGE_STRUCT *AnimRanges = NULL;
diff --git a/src/global/vars.h b/src/global/vars.h
index e97bc1fec..b10f4ab7a 100644
--- a/src/global/vars.h
+++ b/src/global/vars.h
@@ -37,33 +37,20 @@ extern RGB888 GamePalette[256];
 extern bool ModeLock;
 
 extern int32_t NoInputCount;
-extern int32_t IDelay;
+extern bool IDelay;
 extern int32_t IDCount;
 extern INPUT_STATE Input;
 extern INPUT_STATE InputDB;
-extern int32_t KeyChange;
 extern int32_t OptionSelected;
 
 extern bool SoundIsActive;
 extern int16_t SampleLUT[MAX_SAMPLES];
 extern SAMPLE_INFO *SampleInfos;
-extern SAMPLE_DATA **SampleData;
-extern int32_t NumSampleData;
 extern int16_t MusicTrack;
-extern int16_t MusicTrackLooped;
 extern bool MusicLoop;
 extern uint16_t MusicTrackFlags[MAX_CD_TRACKS];
 extern int32_t MnSoundMasterVolume;
 
-extern const char *ATIUserSettingsPath;
-extern const char *T1MUserSettingsPath;
-extern const char *T1MGlobalSettingsPath;
-extern const char *T1MGameflowPath;
-extern const char *T1MGameflowGoldPath;
-
-extern int8_t IsGameWindowActive;
-extern double UITextScale;
-extern double UIBarScale;
 extern TEXTSTRING *AmmoText;
 extern TEXTSTRING *FPSText;
 extern int32_t FPSCounter;
@@ -74,12 +61,10 @@ extern GAMEFLOW GF;
 extern LARA_INFO Lara;
 extern ITEM_INFO *LaraItem;
 extern CAMERA_INFO Camera;
-extern bool CameraUnderwater;
 extern SAVEGAME_INFO SaveGame;
 extern int32_t SavedGamesCount;
 extern int32_t SaveCounter;
 extern int32_t CurrentLevel;
-extern int32_t DemoLevel;
 extern uint32_t *DemoPtr;
 extern int32_t DemoCount;
 extern int32_t LevelComplete;
@@ -109,8 +94,6 @@ extern uint16_t *Overlap;
 extern int16_t *GroundZone[2];
 extern int16_t *GroundZone2[2];
 extern int16_t *FlyZone[2];
-extern int32_t SlotsUsed;
-extern CREATURE_INFO *BaddieSlots;
 extern ANIM_STRUCT *Anims;
 extern ANIM_CHANGE_STRUCT *AnimChanges;
 extern ANIM_RANGE_STRUCT *AnimRanges;
diff --git a/src/specific/output.c b/src/specific/output.c
index 17779e72c..df7b72b7c 100644
--- a/src/specific/output.c
+++ b/src/specific/output.c
@@ -109,11 +109,11 @@ int32_t GetRenderScale(int32_t unit)
     int32_t baseWidth = 640;
     int32_t baseHeight = 480;
     int32_t scale_x = PhdWinWidth > baseWidth
-        ? ((double)PhdWinWidth * unit * UITextScale) / baseWidth
-        : unit * UITextScale;
+        ? ((double)PhdWinWidth * unit * T1MConfig.ui.text_scale) / baseWidth
+        : unit * T1MConfig.ui.text_scale;
     int32_t scale_y = PhdWinHeight > baseHeight
-        ? ((double)PhdWinHeight * unit * UITextScale) / baseHeight
-        : unit * UITextScale;
+        ? ((double)PhdWinHeight * unit * T1MConfig.ui.text_scale) / baseHeight
+        : unit * T1MConfig.ui.text_scale;
     return MIN(scale_x, scale_y);
 }
 
@@ -129,7 +129,8 @@ void BarLocation(
     } else if (
         bar_location == T1M_BL_TOP_RIGHT
         || bar_location == T1M_BL_BOTTOM_RIGHT) {
-        *x = GetRenderWidthDownscaled() - width * UIBarScale - screen_margin_h;
+        *x = GetRenderWidthDownscaled() - width * T1MConfig.ui.bar_scale
+            - screen_margin_h;
     } else {
         *x = (GetRenderWidthDownscaled() - width) / 2;
     }
@@ -138,8 +139,8 @@ void BarLocation(
         || bar_location == T1M_BL_TOP_RIGHT) {
         *y = screen_margin_v + BarOffsetY[bar_location];
     } else {
-        *y = GetRenderHeightDownscaled() - height * UIBarScale - screen_margin_v
-            - BarOffsetY[bar_location];
+        *y = GetRenderHeightDownscaled() - height * T1MConfig.ui.bar_scale
+            - screen_margin_v - BarOffsetY[bar_location];
     }
 
     BarOffsetY[bar_location] += height + bar_spacing;
@@ -182,8 +183,8 @@ void RenderBar(int32_t value, int32_t value_max, int32_t bar_type)
     int32_t border = 1;
     int32_t sx = GetRenderScale(x) - padding;
     int32_t sy = GetRenderScale(y) - padding;
-    int32_t sw = GetRenderScale(width) * UIBarScale + padding * 2;
-    int32_t sh = GetRenderScale(height) * UIBarScale + padding * 2;
+    int32_t sw = GetRenderScale(width) * T1MConfig.ui.bar_scale + padding * 2;
+    int32_t sh = GetRenderScale(height) * T1MConfig.ui.bar_scale + padding * 2;
 
     // border
     S_DrawScreenFlatQuad(
@@ -204,8 +205,8 @@ void RenderBar(int32_t value, int32_t value_max, int32_t bar_type)
 
         sx = GetRenderScale(x);
         sy = GetRenderScale(y);
-        sw = GetRenderScale(width) * UIBarScale;
-        sh = GetRenderScale(height) * UIBarScale;
+        sw = GetRenderScale(width) * T1MConfig.ui.bar_scale;
+        sh = GetRenderScale(height) * T1MConfig.ui.bar_scale;
 
         if (T1MConfig.enable_smooth_bars) {
             for (int i = 0; i < COLOR_STEPS - 1; i++) {
diff --git a/src/specific/shell.c b/src/specific/shell.c
index c0eb41a31..10e206dec 100644
--- a/src/specific/shell.c
+++ b/src/specific/shell.c
@@ -27,6 +27,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+static const char *T1MGameflowPath = "cfg/Tomb1Main_gameflow.json5";
+static const char *T1MGameflowGoldPath = "cfg/Tomb1Main_gameflow_ub.json5";
+
 void GameMain()
 {
     SoundIsActive = true;
diff --git a/src/specific/smain.c b/src/specific/smain.c
index 80f3470b1..d1a46b8a1 100644
--- a/src/specific/smain.c
+++ b/src/specific/smain.c
@@ -20,6 +20,7 @@
 static const char *ClassName = "TRClass";
 static const char *WindowName = "Tomb Raider";
 static UINT CloseMsg = 0;
+static bool IsGameWindowActive = true;
 
 static void WinGameFinish();
 static LRESULT CALLBACK
diff --git a/src/specific/sndpc.c b/src/specific/sndpc.c
index b89a35200..ec204c91f 100644
--- a/src/specific/sndpc.c
+++ b/src/specific/sndpc.c
@@ -48,6 +48,9 @@ typedef struct WAVE_FILE_HEADER {
 static DUPE_SOUND_BUFFER *DupeSoundBufferList = NULL;
 static int32_t DecibelLUT[DECIBEL_LUT_SIZE] = { 0 };
 static int32_t MusicNumTracks = 0;
+static int16_t MusicTrackLooped = 0;
+extern int32_t NumSampleData;
+static SAMPLE_DATA **SampleData = NULL;
 
 int32_t ConvertVolumeToDecibel(int32_t volume)
 {