diff --git a/src/platform/libretro/libretro.c b/src/platform/libretro/libretro.c
index 4b05a422f6b..de4801d3522 100644
--- a/src/platform/libretro/libretro.c
+++ b/src/platform/libretro/libretro.c
@@ -55,6 +55,7 @@ static unsigned targetSampleRate = GBA_RESAMPLED_RATE;
 #define VIDEO_WIDTH_MAX  256
 #define VIDEO_HEIGHT_MAX 224
 #define VIDEO_BUFF_SIZE  (VIDEO_WIDTH_MAX * VIDEO_HEIGHT_MAX * sizeof(mColor))
+#define LIBRETRO_MAX_PORTS 8
 
 static retro_environment_t environCallback;
 static retro_video_refresh_t videoCallback;
@@ -75,6 +76,9 @@ static void _audioRateChanged(struct mAVStream*, unsigned rate);
 static void _setRumble(struct mRumbleIntegrator*, float level);
 static uint8_t _readLux(struct GBALuminanceSource* lux);
 static void _updateLux(struct GBALuminanceSource* lux);
+static int _boktai1StepToBar(int step);
+static int _boktai1BarToStep(int bar);
+static int _analogStickSolarLevel(unsigned port);
 static void _updateCamera(const uint32_t* buffer, unsigned width, unsigned height, size_t pitch);
 static void _startImage(struct mImageSource*, unsigned w, unsigned h, int colorFormats);
 static void _stopImage(struct mImageSource*);
@@ -106,6 +110,8 @@ static int luxLevelIndex;
 static uint8_t luxLevel;
 static bool luxSensorEnabled;
 static bool luxSensorUsed;
+static bool luxAnalogMode;
+static bool boktai1Game;
 static struct mLogger logger;
 static struct retro_camera_callback cam;
 static struct mImageSource imageSource;
@@ -1436,6 +1442,7 @@ void retro_init(void) {
 	envVarsUpdated = true;
 	luxSensorUsed = false;
 	luxSensorEnabled = false;
+	boktai1Game = false;
 	luxLevelIndex = 0;
 	luxLevel = 0;
 	lux.readLuminance = _readLux;
@@ -1607,23 +1614,60 @@ void retro_run(void) {
 	core->setKeys(core, keys);
 
 	if (!luxSensorUsed) {
-		static bool wasAdjustingLux = false;
-		if (wasAdjustingLux) {
-			wasAdjustingLux = inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3) ||
-			                  inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3);
-		} else {
-			if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3)) {
-				++luxLevelIndex;
-				if (luxLevelIndex > 10) {
-					luxLevelIndex = 10;
+		if (luxAnalogMode) {
+			int level = -1;
+			unsigned port;
+			for (port = 0; port < LIBRETRO_MAX_PORTS; ++port) {
+				level = _analogStickSolarLevel(port);
+				if (level >= 0) {
+					break;
+				}
+			}
+			if (level >= 0) {
+				if (boktai1Game) {
+					if (level > 8) {
+						level = 8;
+					}
+					luxLevelIndex = _boktai1BarToStep(level);
+				} else {
+					luxLevelIndex = level;
 				}
-				wasAdjustingLux = true;
-			} else if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3)) {
-				--luxLevelIndex;
-				if (luxLevelIndex < 0) {
-					luxLevelIndex = 0;
+			}
+		} else {
+			static bool wasAdjustingLux = false;
+			if (wasAdjustingLux) {
+				wasAdjustingLux = inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3) ||
+				                  inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3);
+			} else {
+				if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3)) {
+					if (boktai1Game) {
+						int bar = _boktai1StepToBar(luxLevelIndex);
+						if (bar < 8) {
+							++bar;
+						}
+						luxLevelIndex = _boktai1BarToStep(bar);
+					} else {
+						++luxLevelIndex;
+						if (luxLevelIndex > 10) {
+							luxLevelIndex = 10;
+						}
+					}
+					wasAdjustingLux = true;
+				} else if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3)) {
+					if (boktai1Game) {
+						int bar = _boktai1StepToBar(luxLevelIndex);
+						if (bar > 0) {
+							--bar;
+						}
+						luxLevelIndex = _boktai1BarToStep(bar);
+					} else {
+						--luxLevelIndex;
+						if (luxLevelIndex < 0) {
+							luxLevelIndex = 0;
+						}
+					}
+					wasAdjustingLux = true;
 				}
-				wasAdjustingLux = true;
 			}
 		}
 	}
@@ -2088,6 +2132,22 @@ bool retro_load_game(const struct retro_game_info* game) {
 	core->loadROM(core, rom);
 	deferredSetup = true;
 
+	/* Boktai 1 has an 8-bar solar gauge. Detect it once per loaded game so
+	 * manual adjustments (core option level + L3/R3) operate in 0-8 bars. */
+	boktai1Game = false;
+#ifdef M_CORE_GBA
+	if (core->platform(core) == mPLATFORM_GBA) {
+		struct mGameInfo info;
+		core->getGameInfo(core, &info);
+		boktai1Game = strcmp(info.code, "U3IJ") == 0 ||
+		              strcmp(info.code, "U3IE") == 0 ||
+		              strcmp(info.code, "U3IP") == 0;
+	}
+#endif
+	/* Re-apply solar settings with the correct mapping for this title. */
+	envVarsUpdated = true;
+	_updateLux(&lux);
+
 	const char* sysDir = 0;
 	const char* biosName = 0;
 	char biosPath[PATH_MAX];
@@ -2154,6 +2214,7 @@ void retro_unload_game(void) {
 	if (!core) {
 		return;
 	}
+	boktai1Game = false;
 	mCoreConfigDeinit(&core->config);
 	core->deinit(core);
 	mappedMemoryFree(data, dataSize);
@@ -2466,6 +2527,81 @@ static void _setRumble(struct mRumbleIntegrator* rumble, float level) {
 	rumbleCallback(0, RETRO_RUMBLE_WEAK, level * 0xFFFF);
 }
 
+static int _boktai1StepToBar(int step) {
+	static const uint8_t map[11] = { 0, 1, 2, 3, 3, 4, 5, 6, 7, 7, 8 };
+	if (step < 0) {
+		step = 0;
+	} else if (step > 10) {
+		step = 10;
+	}
+	return map[step];
+}
+
+static int _boktai1BarToStep(int bar) {
+	static const uint8_t map[9] = { 0, 1, 2, 3, 5, 6, 7, 8, 10 };
+	if (bar < 0) {
+		bar = 0;
+	} else if (bar > 8) {
+		bar = 8;
+	}
+	return map[bar];
+}
+
+static int _analogStickSolarLevel(unsigned port) {
+	const int16_t dead = 0x4000;
+	int16_t lx = inputCallback(port, RETRO_DEVICE_ANALOG,
+	                           RETRO_DEVICE_INDEX_ANALOG_LEFT,
+	                           RETRO_DEVICE_ID_ANALOG_X);
+	int16_t ly = inputCallback(port, RETRO_DEVICE_ANALOG,
+	                           RETRO_DEVICE_INDEX_ANALOG_LEFT,
+	                           RETRO_DEVICE_ID_ANALOG_Y);
+	int16_t rx = inputCallback(port, RETRO_DEVICE_ANALOG,
+	                           RETRO_DEVICE_INDEX_ANALOG_RIGHT,
+	                           RETRO_DEVICE_ID_ANALOG_X);
+	int16_t ry = inputCallback(port, RETRO_DEVICE_ANALOG,
+	                           RETRO_DEVICE_INDEX_ANALOG_RIGHT,
+	                           RETRO_DEVICE_ID_ANALOG_Y);
+
+	int group = -1;
+	if (ly < -dead) {
+		group = 0; /* 0-3 */
+	} else if (ly > dead) {
+		group = 1; /* 4-7 */
+	} else if (lx < -dead) {
+		group = 2; /* 8-10 & 0 */
+	}
+
+	int select = -1;
+	if (ry < -dead) {
+		select = 0; /* 0/4/8 */
+	} else if (ry > dead) {
+		select = 1; /* 1/5/9 */
+	} else if (rx < -dead) {
+		select = 2; /* 2/6/10 */
+	} else if (rx > dead) {
+		select = 3; /* 3/7/0 */
+	}
+
+	if (group < 0 || select < 0) {
+		return -1;
+	}
+
+	if (group == 0) {
+		return select;
+	} else if (group == 1) {
+		return 4 + select;
+	}
+
+	if (select == 0) {
+		return 8;
+	} else if (select == 1) {
+		return 9;
+	} else if (select == 2) {
+		return 10;
+	}
+	return 0;
+}
+
 static void _updateLux(struct GBALuminanceSource* lux) {
 	UNUSED(lux);
 	struct retro_variable var = {
@@ -2480,6 +2616,7 @@ static void _updateLux(struct GBALuminanceSource* lux) {
 
 	if (luxVarUpdated) {
 		luxSensorUsed = strcmp(var.value, "sensor") == 0;
+		luxAnalogMode = strcmp(var.value, "analog") == 0;
 	}
 
 	if (luxSensorUsed) {
@@ -2487,17 +2624,29 @@ static void _updateLux(struct GBALuminanceSource* lux) {
 		float fLux = luxSensorEnabled ? sensorGetCallback(0, RETRO_SENSOR_ILLUMINANCE) : 0.0f;
 		luxLevel = cbrtf(fLux) * 8;
 	} else {
-		if (luxVarUpdated) {
+		if (luxVarUpdated && !luxAnalogMode) {
 			char* end;
 			int newLuxLevelIndex = strtol(var.value, &end, 10);
 
 			if (!*end) {
-				if (newLuxLevelIndex > 10) {
-					luxLevelIndex = 10;
-				} else if (newLuxLevelIndex < 0) {
-					luxLevelIndex = 0;
+				if (boktai1Game) {
+					/* Boktai 1 shows an 8-bar gauge (0-8). Clamp any user-provided
+					 * values outside that range, then map into the internal 10-step
+					 * lux level indices. */
+					if (newLuxLevelIndex > 8) {
+						newLuxLevelIndex = 8;
+					} else if (newLuxLevelIndex < 0) {
+						newLuxLevelIndex = 0;
+					}
+					luxLevelIndex = _boktai1BarToStep(newLuxLevelIndex);
 				} else {
-					luxLevelIndex = newLuxLevelIndex;
+					if (newLuxLevelIndex > 10) {
+						luxLevelIndex = 10;
+					} else if (newLuxLevelIndex < 0) {
+						luxLevelIndex = 0;
+					} else {
+						luxLevelIndex = newLuxLevelIndex;
+					}
 				}
 			}
 		}
diff --git a/src/platform/libretro/libretro_core_options.h b/src/platform/libretro/libretro_core_options.h
index 9bd553bdf23..01a814dbd70 100644
--- a/src/platform/libretro/libretro_core_options.h
+++ b/src/platform/libretro/libretro_core_options.h
@@ -271,11 +271,12 @@ struct retro_core_option_v2_definition option_defs_us[] = {
       "mgba_solar_sensor_level",
       "Solar Sensor Level",
       NULL,
-      "Sets ambient sunlight intensity. Can be used by games that included a solar sensor in their cartridges, e.g: the Boktai series.",
+      "Sets sunlight intensity for games that include a solar sensor in their cartridge (e.g. Boktai). 'Analog Stick Control': left stick selects group (Up=0-3, Down=4-7, Left=8-10/0); right stick selects value (Up=0/4/8, Down=1/5/9, Left=2/6/10, Right=3/7/0). ASC disables Analog to Digital until restart.",
       NULL,
       "input",
       {
-         { "sensor", "Use device sensor if available" },
+         { "sensor", "Use Device Sensor If Available" },
+         { "analog", "Analog Stick Control" },
          { "0",      NULL },
          { "1",      NULL },
          { "2",      NULL },