--- a/sources/auxiliar.cpp
+++ b/sources/auxiliar.cpp
@@ -20,7 +20,8 @@
 char *strupr(char *ptr)
 {
     if (ptr!=0) {
-        char *p=new char[strlen(ptr)+1];
+        /* the original walked a new, uninitialized buffer: upper-case the string in place instead */
+        char *p=ptr;
         
         while(*p!=0) {
             *p=toupper(*p);
--- a/sources/configuration.cpp
+++ b/sources/configuration.cpp
@@ -29,10 +29,15 @@
 		return false;
 	} /* if */ 
 
-	if (2!=fscanf(fp,"%i %i",&fullscreen,&PIXEL_SIZE)) {
-		fclose(fp);
-		return false;
-	} /* if */ 
+	{
+		/* the original read "%i" straight into the bool */
+		int fs;
+		if (2!=fscanf(fp,"%i %i",&fs,&PIXEL_SIZE)) {
+			fclose(fp);
+			return false;
+		} /* if */ 
+		fullscreen=(fs!=0);
+	}
 
 	THRUST_KEY=(SDLKey)a;
 	ANTITHRUST_KEY=(SDLKey)b;
--- a/sources/game.cpp
+++ b/sources/game.cpp
@@ -93,9 +93,15 @@
 int replay_source=0;
 
 
+#ifdef __EMSCRIPTEN__
+SDLKey THRUST_KEY=SDLK_UP,ANTITHRUST_KEY=SDLK_DOWN,LEFT_KEY=SDLK_LEFT,RIGHT_KEY=SDLK_RIGHT;
+SDLKey FIRE_KEY=SDLK_SPACE,ATRACTOR_KEY=SDLK_RETURN;
+SDLKey PAUSE_KEY=SDLK_p;
+#else
 SDLKey THRUST_KEY=SDLK_q,ANTITHRUST_KEY=SDLK_a,LEFT_KEY=SDLK_o,RIGHT_KEY=SDLK_p;
 SDLKey FIRE_KEY=SDLK_SPACE,ATRACTOR_KEY=SDLK_RETURN;
 SDLKey PAUSE_KEY=SDLK_F1;
+#endif
 bool pause2=false;
 
 unsigned char old_keyboard[SDLK_LAST];
--- a/sources/main.cpp
+++ b/sources/main.cpp
@@ -47,7 +47,16 @@
 int frames_per_sec_tmp=0;
 int init_time=0;
 
-char *datadir="/usr/share/games/supertransball2/";
+#ifdef __EMSCRIPTEN__
+/* fredygames.com browser build: the data is preloaded at /data, and the page keeps $HOME/.supertransball2
+   (configuration, replays) in the browser's IndexedDB. The window keys (Alt+Enter, Alt+1..4, F12) are off:
+   the page scales the game itself and there is nothing to quit to. */
+#define ST2_WINDOW_KEYS 0
+char *datadir="/data/";
+#else
+#define ST2_WINDOW_KEYS 1
+char *datadir="/usr/share/games/supertransball2/";
+#endif
 char *confdir;
 
 /* Surfaces: */ 
@@ -147,7 +156,12 @@
 	if (!cfg)
 	{
 		cfg=fopen("transball.cfg", "w");
-                fprintf(cfg,"%s","113 97 111 112 32 13 282");
+#ifdef __EMSCRIPTEN__
+                /* arrow keys to fly, Space to fire, Enter for the tractor beam, P to pause */
+                fprintf(cfg,"%s","273 274 276 275 32 13 112");
+#else
+                fprintf(cfg,"%s","113 97 111 112 32 13 282");
+#endif
 	}
 
 	fclose(cfg);
@@ -161,6 +175,10 @@
     bool quit = false;
 
 	if (!load_configuration()) save_configuration();
+#ifdef __EMSCRIPTEN__
+	fullscreen=false;
+	PIXEL_SIZE=1;
+#endif
 
 	time=init_time=GetTickCount();
 	screen_sfc = initializeSDL((fullscreen ? SDL_FULLSCREEN : 0));
@@ -178,10 +196,10 @@
 
 						modifiers=SDL_GetModState();
 
-						if (event.key.keysym.sym==SDLK_F12) quit = true;
+						if (ST2_WINDOW_KEYS && event.key.keysym.sym==SDLK_F12) quit = true;
 
 						
-						if ((modifiers&KMOD_ALT)!=0) {
+						if (ST2_WINDOW_KEYS && (modifiers&KMOD_ALT)!=0) {
 							if (event.key.keysym.sym==SDLK_RETURN) {
 								/* Toogle FULLSCREEN mode: */ 
 								finalizeSDL();
--- a/sources/state_instructions.cpp
+++ b/sources/state_instructions.cpp
@@ -88,10 +88,18 @@
 		font_print(16,10,"              SUPER TRANSBALL 2 V1.5",screen);
 
 		font_print(16,30,"  THE CONTROLS OF THE SHIP ARE [REDEFINIBLE]:",screen);
+#ifdef __EMSCRIPTEN__
+		/* the browser build starts with the arrow keys (see game.cpp) */
+		font_print(16,50,"    UP  - PROPULSORS",screen);
+		font_print(16,60,"   DOWN - RETROPROPULSORS [NOT ALL THE SHIPS]",screen);
+		font_print(16,70,"   LEFT - TURN LEFT",screen);
+		font_print(16,80,"  RIGHT - TURN RIGHT",screen);
+#else
 		font_print(16,50,"    Q   - PROPULSORS",screen);
 		font_print(16,60,"    A   - RETROPROPULSORS [NOT ALL THE SHIPS]",screen);
 		font_print(16,70,"    O   - TURN LEFT",screen);
 		font_print(16,80,"    P   - TURN RIGHT",screen);
+#endif
 		font_print(16,90,"  SPACE - FIRE",screen);
 		font_print(16,100,"  ENTER - BALL ATRACTOR",screen);