diff --git a/android/app/src/main/java/io/github/kichikuou/system3/Launcher.kt b/android/app/src/main/java/io/github/kichikuou/system3/Launcher.kt
index cf41710..61a6b3e 100644
--- a/android/app/src/main/java/io/github/kichikuou/system3/Launcher.kt
+++ b/android/app/src/main/java/io/github/kichikuou/system3/Launcher.kt
@@ -187,15 +187,14 @@ class Launcher private constructor(private val rootDir: File) {
             val configWriter = GameConfigWriter()
             forEachZipEntry(input) { zipEntry, zip ->
                 Log.i("extractFiles", zipEntry.name)
-                val path = File(outDir, zipEntry.name)
+                val entryName = File(zipEntry.name).name
                 if (zipEntry.isDirectory)
                     return@forEachZipEntry
-                path.parentFile.mkdirs()
-                handler.sendMessage(handler.obtainMessage(PROGRESS, zipEntry.name))
-                FileOutputStream(path).buffered().use {
+                handler.sendMessage(handler.obtainMessage(PROGRESS, entryName))
+                FileOutputStream(File(outDir, entryName)).buffered().use {
                     zip.copyTo(it)
                 }
-                configWriter.maybeAdd(zipEntry.name)
+                configWriter.maybeAdd(entryName)
             }
             configWriter.write(outDir)
             handler.sendMessage(handler.obtainMessage(SUCCESS, outDir))
@@ -212,36 +211,17 @@ class Launcher private constructor(private val rootDir: File) {
 
     class InstallFailureException(val msgId: Int) : Exception()
 
-    // A helper class which generates xsystem35.gr and playlist.txt in the game root directory.
+    // A helper class which generates playlist.txt in the game root directory.
     private class GameConfigWriter {
-        private val grb = StringBuilder()
-        private var basename: String? = null
-        private val aldRegex = """(.*?)([a-z])([a-z])\.ald""".toRegex(RegexOption.IGNORE_CASE)
-        private val resourceType = mapOf(
-                "d" to "Data",
-                "g" to "Graphics",
-                "m" to "Midi",
-                "r" to "Resource",
-                "s" to "Scenario",
-                "w" to "Wave")
-
+        private var hasAdisk = false
         private val audioRegex = """.*?(\d+)\.(wav|mp3|ogg)""".toRegex(RegexOption.IGNORE_CASE)
         private val audioFiles: Array<String?> = arrayOfNulls(100)
 
         fun maybeAdd(path: String) {
             val name = File(path).name
 
-            if (name.toLowerCase(Locale.US) == "system39.ain") {
-                grb.appendln("Ain $path")
-                return
-            }
-            aldRegex.matchEntire(name)?.let {
-                val type = resourceType[it.groupValues[2].toLowerCase(Locale.US)]
-                val id = it.groupValues[3].toUpperCase(Locale.US)
-                if (type != null) {
-                    grb.appendln("$type$id $path")
-                    basename = it.groupValues[1]
-                }
+            if (name.toLowerCase(Locale.US) == "adisk.dat") {
+                hasAdisk = true
             }
             audioRegex.matchEntire(name)?.let {
                 val track = it.groupValues[1].toInt()
@@ -251,14 +231,9 @@ class Launcher private constructor(private val rootDir: File) {
         }
 
         fun write(outDir: File) {
-            basename ?: throw InstallFailureException(R.string.cannot_find_adisk)
-            for (id in 'A' .. 'Z') {
-                grb.appendln("Save$id ../save/${basename}s${id.toLowerCase()}.asd")
+            if (!hasAdisk) {
+                throw InstallFailureException(R.string.cannot_find_adisk)
             }
-            val gr = grb.toString()
-            Log.i("xsystem35.gr", gr)
-            File(outDir, "xsystem35.gr").writeText(gr)
-
             val playlist = audioFiles.joinToString("\n") { it ?: "" }.trimEnd('\n')
             File(outDir, PLAYLIST_FILE).writeText(playlist)
         }
diff --git a/src/sdlmain.cpp b/src/sdlmain.cpp
index 0534b9a..9cc0c52 100644
--- a/src/sdlmain.cpp
+++ b/src/sdlmain.cpp
@@ -15,12 +15,6 @@ SDL_Window* g_window;
 
 int main(int argc, char *argv[])
 {
-#ifdef __ANDROID__
-	// Chdir to the internal storage path where the launcher should have placed
-	// game files.
-	chdir(SDL_AndroidGetInternalStoragePath());
-#endif
-
 	SDL_Init(SDL_INIT_VIDEO);
 
 	// ウィンドウ表示
@@ -38,11 +32,13 @@ int main(int argc, char *argv[])
 	const char *fontfile = DEFAULT_FONT_PATH "MTLc3m.ttf";
 
 	for (int i = 1; i < argc; i++) {
-		if (strcmp(argv[i], "-antialias") == 0)
+		if (strcmp(argv[i], "-gamedir") == 0)
+			chdir(argv[++i]);
+		else if (strcmp(argv[i], "-antialias") == 0)
 			ags_setAntialiasedStringMode(1);
-		if (strcmp(argv[i], "-savedir") == 0)
+		else if (strcmp(argv[i], "-savedir") == 0)
 			FILEIO::SetSaveDir(argv[++i]);
-		if (strcmp(argv[i], "-fontfile") == 0)
+		else if (strcmp(argv[i], "-fontfile") == 0)
 			fontfile = argv[++i];
 	}