--- a/configure.ac
+++ b/configure.ac
@@ -115,10 +115,11 @@
 
 # TODO: We currently link everything against libraries that don't need it.
 # Use the specific library CFLAGS/LIBS variables instead of setting them here.
-EMFLAGS="-gsource-map -s INVOKE_RUN=1 -s USE_SDL=2 -s USE_SDL_MIXER=2 -s LEGACY_GL_EMULATION=0 -s USE_SDL_NET=2 -s ASSERTIONS=0 -s WASM=1 -s ALLOW_MEMORY_GROWTH=0 -s FORCE_FILESYSTEM=1 -s EXTRA_EXPORTED_RUNTIME_METHODS=[['FS','ccall']] -s SAFE_HEAP=1 -s EXIT_RUNTIME=1 -s STACK_OVERFLOW_CHECK=1 -s PROXY_POSIX_SOCKETS=0 -s USE_PTHREADS=0 -s PROXY_TO_PTHREAD=0 -s TOTAL_MEMORY=64MB -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s ASYNCIFY -O3 --source-map-base /"
+# Browser Games Now, 2026-10-20: SDK 3.1.57, local files and IDBFS saves.
+EMFLAGS="-sUSE_SDL=2 -sUSE_SDL_MIXER=2 -sUSE_SDL_NET=2 -sSDL2_MIXER_FORMATS=[] -sALLOW_MEMORY_GROWTH=1 -sFORCE_FILESYSTEM=1 -sEXPORTED_RUNTIME_METHODS=FS,callMain,addRunDependency,removeRunDependency -sEXIT_RUNTIME=1 -sASYNCIFY -O3"
 
 CFLAGS="$CFLAGS $SDL_CFLAGS ${SAMPLERATE_CFLAGS:-} ${PNG_CFLAGS:-} $EMFLAGS"
-LDFLAGS="$LDFLAGS $SDL_LIBS ${SAMPLERATE_LIBS:-} ${PNG_LIBS:-} $EMFLAGS -lwebsocket.js"
+LDFLAGS="$LDFLAGS $SDL_LIBS ${SAMPLERATE_LIBS:-} ${PNG_LIBS:-} $EMFLAGS -lwebsocket.js -lidbfs.js"
 
 AC_CHECK_LIB(m, log)
 
--- a/src/doom/d_main.c
+++ b/src/doom/d_main.c
@@ -1700,8 +1700,11 @@
     if (gameaction != ga_loadgame) {
         if (autostart || netgame)
             G_InitNew(startskill, startepisode, startmap);
-        else
-            D_StartTitle(); // start up intro loop
+        else {
+            D_StartTitle();
+            // Browser Games Now, 2026-10-20: open the native menu immediately.
+            M_StartControlPanel();
+        }
     }
 
     D_DoomLoop(); // never returns
--- a/src/doom/g_game.c
+++ b/src/doom/g_game.c
@@ -1482,6 +1482,8 @@
 
     remove(savegame_file);
     rename(temp_savegame_file, savegame_file);
+    // Browser Games Now, 2026-10-20: persist native saves after the rename.
+    EM_ASM({ Module.persistSaves(); });
 
     gameaction = ga_nothing;
     M_StringCopy(savedescription, "", sizeof(savedescription));