--- a/gamma256/gameSource/game.cpp
+++ b/gamma256/gameSource/game.cpp
@@ -30,6 +30,7 @@
 
 
 #include <SDL/SDL.h>
+#include <emscripten.h>
 
 #include "blowUp.h"
 #include "World.h"
@@ -118,8 +119,8 @@
 
 char getKeyDown( int inKeyCode ) {
     SDL_PumpEvents();
-	Uint8 *keys = SDL_GetKeyState( NULL );
-	return keys[ inKeyCode ] == SDL_PRESSED;
+	const Uint8 *keys = SDL_GetKeyboardState( NULL );
+	return keys[ SDL_GetScancodeFromKey( inKeyCode ) ] != 0;
     }
 
 
@@ -176,7 +177,8 @@
     SDL_Event event;
     
     while( true ) {
-        while( SDL_WaitEvent( &event ) ) {
+        // the browser build has no blocking wait: poll and give the page the turn
+        while( SDL_PollEvent( &event ) || ( emscripten_sleep( 20 ), true ) ) {
             switch( event.type ) {
                 case SDL_JOYHATMOTION:
                 case SDL_JOYBUTTONDOWN:
@@ -205,37 +207,25 @@
 
 
 
-// flips back buffer onto screen (or updates rect)
-void flipScreen( SDL_Surface *inScreen ) {
+// SDL 2: the game draws on a software surface and this copies it to the window
+SDL_Window *window = NULL;
 
-    // unlock the screen if necessary
-    if( SDL_MUSTLOCK( inScreen ) ) {
-        SDL_UnlockSurface( inScreen );
-        }
-    
-    if( ( inScreen->flags & SDL_DOUBLEBUF ) == SDL_DOUBLEBUF ) {
-        // need to flip buffer
-        SDL_Flip( inScreen );	
-        }
-    else if( !blowUpChanged ) {
-        // just update center
-
-        // small area in center that we actually draw in, black around it
-        int yOffset = ( inScreen->h - totalImageHeight * blowUpFactor ) / 2;
-        int xOffset = ( inScreen->w - width * blowUpFactor ) / 2;
-        
-        SDL_UpdateRect( inScreen, xOffset, yOffset, 
-                        width * blowUpFactor, 
-                        totalImageHeight * blowUpFactor );	
-        }
-    else {
-        // update the whole thing
-        SDL_UpdateRect( inScreen, 0, 0, inScreen->w, inScreen->h );
-        
-        // reset flag
-        blowUpChanged = false;
+// flips back buffer onto screen
+void flipScreen( SDL_Surface *inScreen ) {
+    // the game draws 0x00RRGGBB; the window surface of the browser build is 0x00BBGGRR
+    SDL_Surface *windowSurface = SDL_GetWindowSurface( window );
+    for( int y=0; y<inScreen->h; y++ ) {
+        Uint32 *from = (Uint32 *)( (char *)inScreen->pixels
+                                   + y * inScreen->pitch );
+        Uint32 *to = (Uint32 *)( (char *)windowSurface->pixels
+                                 + y * windowSurface->pitch );
+        for( int x=0; x<inScreen->w; x++ ) {
+            Uint32 p = from[x];
+            to[x] = ( ( p & 0xFF ) << 16 ) | ( p & 0xFF00 )
+                | ( ( p >> 16 ) & 0xFF );
+            }
         }
-    
+    SDL_UpdateWindowSurface( window );
     }
 
 
@@ -311,22 +301,18 @@
     int displayW = width * blowUpFactor;
     int displayH = totalImageHeight * blowUpFactor;
 
-    
-    Uint32 flags = SDL_HWSURFACE | SDL_DOUBLEBUF;
-    if( fullScreen ) {
-        flags = flags | SDL_FULLSCREEN;
-    
-        // use letterbox mode in full screen
-        displayW = screenWidth;
-        displayH = screenHeight;
+    if( window == NULL ) {
+        window = SDL_CreateWindow( "Passage", SDL_WINDOWPOS_UNDEFINED,
+                                   SDL_WINDOWPOS_UNDEFINED,
+                                   displayW, displayH, 0 );
+        }
+    else {
+        SDL_SetWindowSize( window, displayW, displayH );
         }
-    
-    
 
-    screen = SDL_SetVideoMode( displayW, displayH, 
-                               32, 
-                               flags );
-    
+    screen = SDL_CreateRGBSurface( 0, displayW, displayH, 32,
+                                   0x00FF0000, 0x0000FF00, 0x000000FF, 0 );
+
     if ( screen == NULL ) {
         printf( "Couldn't set %dx%dx32 video mode: %s\n", displayW, 
                 displayH,
@@ -966,38 +952,7 @@
             }
 
         
-        if( getKeyDown( SDLK_b ) ) {
-            // adjust blowup factor
-            blowUpFactor += blowUpStep;
-            
-            if( blowUpFactor > maxBlowUpFactor ) {
-                blowUpStep *= -1;
-                blowUpFactor = maxBlowUpFactor - 1;
-                }
-            
-            if( blowUpFactor < 1 ) {
-                blowUpStep *= -1;
-                blowUpFactor = 2;
-                }
-
-            if( fullScreen ) {                
-                // force redraw of whole screen
-                blowUpChanged = true;
-                }
-            else {
-                // create a new screen using the new size
-                createScreen();
-                }
-
-            }
-
-        if( getKeyDown( SDLK_f ) ) {
-            // toggle fullscreen mode
-            fullScreen = ! fullScreen;
-            
-            // create a new screen surface (and destroy old one)
-            createScreen();
-            }
+        // (the B key for zoom and the F key for full screen are off in the browser build)
         
             
 
@@ -1131,8 +1086,7 @@
                     switch( event.key.keysym.sym ) {
                         case SDLK_q:
                         case SDLK_ESCAPE:
-                            done = true;
-                            quit = true;
+                            // no quitting in the browser (it would leave a dead page)
                             break;
                         default:
                             break;
--- a/minorGems/system/linux/ThreadLinux.cpp	2005-01-22 19:15:06.000000000 -0200
+++ b/minorGems/system/linux/ThreadLinux.cpp	2026-11-01 20:48:37.855771112 -0300
@@ -31,6 +31,9 @@
 
 #include <unistd.h>
 #include <time.h>
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
 #include <stdio.h>
 
 
@@ -116,6 +119,12 @@
 
 void Thread::staticSleep( unsigned long inTimeInMilliseconds ) {
 
+#ifdef __EMSCRIPTEN__
+    // the browser build sleeps by giving the turn back to the page (Asyncify)
+    emscripten_sleep( inTimeInMilliseconds );
+    return;
+#endif
+
     unsigned long seconds = inTimeInMilliseconds / 1000;
     unsigned long milliseconds = inTimeInMilliseconds % 1000;