diff --git a/cmake/AssetCache.cmake b/cmake/AssetCache.cmake
new file mode 100644
index 0000000..4c9aca6
--- /dev/null
+++ b/cmake/AssetCache.cmake
@@ -0,0 +1,13 @@
+function(GetFromAssetCache CACHE FILENAME SALT OUTPUT_PATH_VAR OUTPUT_HASH_VAR)
+  file(SHA256 ${FILENAME} HASH)
+  string(SHA1 HASHED_SALT ${SALT})
+  if (EXISTS ${CACHE}/${HASH}-${HASHED_SALT})
+    set(${OUTPUT_PATH_VAR} ${CACHE}/${HASH}-${HASHED_SALT} PARENT_SCOPE)
+  endif()
+  set(${OUTPUT_HASH_VAR} ${HASH} PARENT_SCOPE)
+endfunction()
+
+function(AddToAssetCache CACHE HASH SALT FILENAME)
+  string(SHA1 HASHED_SALT ${SALT})
+  configure_file(${FILENAME} ${CACHE}/${HASH}-${HASHED_SALT} COPYONLY)
+endfunction()
diff --git a/cmake/FlacToOgg.cmake b/cmake/FlacToOgg.cmake
index 941f9c3..593d476 100644
--- a/cmake/FlacToOgg.cmake
+++ b/cmake/FlacToOgg.cmake
@@ -1,14 +1,26 @@
+set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
+include(AssetCache)
+
 find_program(OGGENC NAMES oggenc NO_CMAKE_FIND_ROOT_PATH)
 if(OGGENC)
   file(GLOB_RECURSE FLAC_FILES RELATIVE ${DATADIR} ${DATADIR}/*.flac)
   message(STATUS "FlacToOgg engaging... (using ${OGGENC})")
   foreach(file IN LISTS FLAC_FILES)
     message(STATUS ${file})
-    execute_process(COMMAND ${OGGENC} -Q -b 192 --resample 44100 ${file} WORKING_DIRECTORY ${DATADIR}  RESULT_VARIABLE OGGENC_RESULT)
-    if(OGGENC_RESULT)
-      message(WARNING "ERROR: ${OGGENC_RESULT}")
-    else()
+    string(REGEX REPLACE "^(.+)(\\.[^.]+)$" "\\1" filename ${file})
+    GetFromAssetCache(${CACHE} ${DATADIR}/${file} "ogg-${BITRATE}-${SAMPLERATE}" CACHED HASH)
+    if (CACHED)
       file(REMOVE ${DATADIR}/${file})
+      configure_file(${CACHED} ${DATADIR}/${filename}.ogg COPYONLY)
+      unset(CACHED)
+    else()
+      execute_process(COMMAND ${OGGENC} -Q -b ${BITRATE} --resample ${SAMPLERATE} ${file} -o ${filename}.ogg WORKING_DIRECTORY ${DATADIR} RESULT_VARIABLE OGGENC_RESULT)
+      if(OGGENC_RESULT)
+        message(WARNING "ERROR: ${OGGENC_RESULT}")
+      else()
+        file(REMOVE ${DATADIR}/${file})
+        AddToAssetCache(${CACHE} ${HASH} "ogg-${BITRATE}-${SAMPLERATE}" "${DATADIR}/${filename}.ogg")
+      endif()
     endif()
   endforeach(file)
 else(OGGENC)
diff --git a/cmake/FlacToOpus.cmake b/cmake/FlacToOpus.cmake
new file mode 100644
index 0000000..426be98
--- /dev/null
+++ b/cmake/FlacToOpus.cmake
@@ -0,0 +1,28 @@
+set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
+include(AssetCache)
+
+find_program(OPUSENC NAMES opusenc NO_CMAKE_FIND_ROOT_PATH)
+if(OPUSENC)
+  file(GLOB_RECURSE FLAC_FILES RELATIVE ${DATADIR} ${DATADIR}/*.flac)
+  message(STATUS "FlacToOpus engaging... (using ${OPUSENC})")
+  foreach(file IN LISTS FLAC_FILES)
+    message(STATUS ${file})
+    string(REGEX REPLACE "^(.+)(\\.[^.]+)$" "\\1" filename ${file})
+    GetFromAssetCache(${CACHE} ${DATADIR}/${file} "opus-${BITRATE}" CACHED HASH)
+    if (CACHED)
+      file(REMOVE ${DATADIR}/${file})
+      configure_file(${CACHED} ${DATADIR}/${filename}.opus COPYONLY)
+      unset(CACHED)
+    else()
+      execute_process(COMMAND ${OPUSENC} --quiet --bitrate ${BITRATE} ${file} ${filename}.opus WORKING_DIRECTORY ${DATADIR} RESULT_VARIABLE OPUSENC_RESULT)
+      if(OPUSENC_RESULT)
+        message(WARNING "ERROR: ${OPUSENC_RESULT}")
+      else()
+        file(REMOVE ${DATADIR}/${file})
+        AddToAssetCache(${CACHE} ${HASH} "opus-${BITRATE}" "${DATADIR}/${filename}.opus")
+      endif()
+    endif()
+  endforeach(file)
+else(OPUSENC)
+  message(WARNING "FlacToOpus: can't find opusenc!")
+endif(OPUSENC)
diff --git a/cmake/ImgToWebp.cmake b/cmake/ImgToWebp.cmake
new file mode 100644
index 0000000..052746c
--- /dev/null
+++ b/cmake/ImgToWebp.cmake
@@ -0,0 +1,37 @@
+set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
+include(AssetCache)
+
+find_program(CONVERT NAMES convert NO_CMAKE_FIND_ROOT_PATH)
+if(CONVERT)
+  file(GLOB_RECURSE IMAGE_FILES RELATIVE ${DATADIR} ${DATADIR}/*.png ${DATADIR}/*.jpg ${DATADIR}/*.JPG ${DATADIR}/*.webp)
+  message(STATUS "ImgToWebp engaging... (using ${CONVERT})")
+  foreach(file IN LISTS IMAGE_FILES)
+    if (NOT file MATCHES "^icons/")
+      message(STATUS ${file})
+      string(REGEX REPLACE "^(.+)(\\.[^.]+)$" "\\1" filepath ${file})
+      if (RESIZE)
+        set(resizecmd -resize ${RESIZE})
+      else()
+        set(resizecmd "")
+      endif()
+      GetFromAssetCache(${CACHE} ${DATADIR}/${file} "${QUALITY}-${RESIZE}-${PARAMS}" CACHED HASH)
+      if (CACHED)
+        file(REMOVE ${DATADIR}/${file})
+        configure_file(${CACHED} ${DATADIR}/${filepath}.wbp COPYONLY)
+        unset(CACHED)
+      else()
+        separate_arguments(PARAMS)
+        set(CONVERT_CMD ${CONVERT} ${file} -quality ${QUALITY} ${PARAMS} ${resizecmd} webp:${filepath}.wbp)
+        execute_process(COMMAND ${CONVERT_CMD} WORKING_DIRECTORY ${DATADIR} RESULT_VARIABLE CONVERT_RESULT)
+        if(CONVERT_RESULT)
+          message(WARNING "ERROR: ${CONVERT_RESULT}")
+        else()
+          file(REMOVE ${DATADIR}/${file})
+          AddToAssetCache(${CACHE} ${HASH} "${QUALITY}-${RESIZE}-${PARAMS}" "${DATADIR}/${filepath}.wbp")
+        endif()
+      endif()
+    endif()
+  endforeach(file)
+else(CONVERT)
+  message(WARNING "ImgToWebp: can't find convert!")
+endif(CONVERT)
diff --git a/cmake/libsuperderpy.cmake b/cmake/libsuperderpy.cmake
index ce79879..d239d16 100644
--- a/cmake/libsuperderpy.cmake
+++ b/cmake/libsuperderpy.cmake
@@ -314,16 +314,28 @@ if (NOT LIBSUPERDERPY_CONFIG_INCLUDED)
 
 	if (ANDROID OR EMSCRIPTEN)
 		if (ANDROID)
-			set(FLACTOOGG_DATADIR "${CMAKE_BINARY_DIR}/android/assets/data")
-			set(FLACTOOGG_DEPEND "")
+			set(ASSET_PIPELINE_DATADIR "${CMAKE_BINARY_DIR}/android/assets/data")
+			set(ASSET_PIPELINE_DEPEND "")
 		else (EMSCRIPTEN)
-			set(FLACTOOGG_DATADIR "${CMAKE_INSTALL_PREFIX}/share/${LIBSUPERDERPY_GAMENAME}/data")
-			set(FLACTOOGG_DEPEND ${LIBSUPERDERPY_GAMENAME}_install)
+			set(ASSET_PIPELINE_DATADIR "${CMAKE_INSTALL_PREFIX}/share/${LIBSUPERDERPY_GAMENAME}/data")
+			set(ASSET_PIPELINE_DEPEND ${LIBSUPERDERPY_GAMENAME}_install)
 		endif()
 
-		add_custom_target(${LIBSUPERDERPY_GAMENAME}_flac_to_ogg
-			DEPENDS ${FLACTOOGG_DEPEND}
-			COMMAND ${CMAKE_COMMAND} -DDATADIR=${FLACTOOGG_DATADIR} -P ${LIBSUPERDERPY_DIR}/cmake/FlacToOgg.cmake)
+		set(FLACTOOPUS_BITRATE "192" CACHE STRING "Bitrate of resulting Opus files (kbps)")
+
+		add_custom_target(${LIBSUPERDERPY_GAMENAME}_flac_to_opus
+			DEPENDS ${ASSET_PIPELINE_DEPEND}
+			COMMAND ${CMAKE_COMMAND} -DDATADIR=${ASSET_PIPELINE_DATADIR} -DCACHE="${CMAKE_SOURCE_DIR}/.assetcache" -DBITRATE=${FLACTOOPUS_BITRATE} -P ${LIBSUPERDERPY_DIR}/cmake/FlacToOpus.cmake
+			USES_TERMINAL)
+
+		set(IMGTOWEBP_QUALITY "75" CACHE STRING "Quality of resulting WebP files")
+		set(IMGTOWEBP_RESIZE "" CACHE STRING "Value passed as -resize to ImageMagick (no resizing when empty)")
+		set(IMGTOWEBP_PARAMS "" CACHE STRING "Additional ImageMagick parameters")
+
+		add_custom_target(${LIBSUPERDERPY_GAMENAME}_img_to_webp
+			DEPENDS ${ASSET_PIPELINE_DEPEND}
+			COMMAND ${CMAKE_COMMAND} -DQUALITY="${IMGTOWEBP_QUALITY}" -DRESIZE="${IMGTOWEBP_RESIZE}" -DPARAMS="${IMGTOWEBP_PARAMS}" -DCACHE="${CMAKE_SOURCE_DIR}/.assetcache" -DDATADIR=${ASSET_PIPELINE_DATADIR} -P ${LIBSUPERDERPY_DIR}/cmake/ImgToWebp.cmake
+			USES_TERMINAL)
 
 	endif(ANDROID OR EMSCRIPTEN)
 
@@ -335,22 +347,25 @@ if (NOT LIBSUPERDERPY_CONFIG_INCLUDED)
 			set(APK_PATH ${CMAKE_BINARY_DIR}/android/bin/${LIBSUPERDERPY_GAMENAME}-debug.apk)
 
 			add_custom_target(${LIBSUPERDERPY_GAMENAME}_apk ALL
-				DEPENDS ${EXECUTABLE} ${LIBSUPERDERPY_GAMENAME}_flac_to_ogg
+				DEPENDS ${EXECUTABLE} ${LIBSUPERDERPY_GAMENAME}_flac_to_opus ${LIBSUPERDERPY_GAMENAME}_img_to_webp
 				BYPRODUCTS ${APK_PATH}
 				WORKING_DIRECTORY "${CMAKE_BINARY_DIR}/android"
 				COMMAND ${ANT_COMMAND} debug
+				USES_TERMINAL
 				)
 
 			add_custom_target(${LIBSUPERDERPY_GAMENAME}_install_apk
 				DEPENDS ${LIBSUPERDERPY_GAMENAME}_apk
 				WORKING_DIRECTORY "${CMAKE_BINARY_DIR}/android"
 				COMMAND adb -d install -r ${APK_PATH}
+				USES_TERMINAL
 				)
 
 			add_custom_target(${LIBSUPERDERPY_GAMENAME}_run_apk
 				DEPENDS ${LIBSUPERDERPY_GAMENAME}_install_apk
 				COMMAND adb -d shell
 				'am start -a android.intent.action.MAIN -n ${LIBSUPERDERPY_APPID}/net.dosowisko.libsuperderpy.Activity'
+				USES_TERMINAL
 				)
 
 		else(ANDROID)
@@ -371,9 +386,10 @@ if (NOT LIBSUPERDERPY_CONFIG_INCLUDED)
 
 
 			add_custom_target(${LIBSUPERDERPY_GAMENAME}_js
-				DEPENDS ${LIBSUPERDERPY_GAMENAME}_install ${LIBSUPERDERPY_GAMENAME}_flac_to_ogg
+				DEPENDS ${LIBSUPERDERPY_GAMENAME}_install ${LIBSUPERDERPY_GAMENAME}_flac_to_opus ${LIBSUPERDERPY_GAMENAME}_img_to_webp
 				WORKING_DIRECTORY "${CMAKE_INSTALL_PREFIX}/${LIBSUPERDERPY_GAMENAME}"
 				COMMAND "${CMAKE_C_COMPILER}" ${CFLAGS_LIST} ../bin/${LIBSUPERDERPY_GAMENAME}${CMAKE_EXECUTABLE_SUFFIX} ../lib/libsuperderpy${CMAKE_SHARED_LIBRARY_SUFFIX} ../lib/libsuperderpy-${LIBSUPERDERPY_GAMENAME}${CMAKE_SHARED_LIBRARY_SUFFIX} ${ALLEGRO5_LIBS} ${EMSCRIPTEN_FLAGS} -s MAIN_MODULE=1 -s TOTAL_MEMORY=${EMSCRIPTEN_TOTAL_MEMORY_BYTES} -o ${LIBSUPERDERPY_GAMENAME}.html --preload-file ../share/${LIBSUPERDERPY_GAMENAME}/data --preload-file gamestates@/
+				USES_TERMINAL
 				VERBATIM
 				)
 		endif(EMSCRIPTEN)
diff --git a/src/internal.c b/src/internal.c
index 2866096..bed8809 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -649,6 +649,9 @@ SYMBOL_INTERNAL ALLEGRO_BITMAP* AddBitmap(struct Game* game, char* filename) {
 		rc->counter = 1;
 		rc->id = strdup(filename);
 		rc->data = al_load_bitmap(GetDataFilePath(game, filename));
+		if (!rc->data) {
+			FatalError(game, false, "Bitmap %s (%s) failed to load.", filename, GetDataFilePath(game, filename));
+		}
 		game->_priv.bitmaps[bucket] = AddToList(game->_priv.bitmaps[bucket], rc);
 	}
 	return rc->data;
diff --git a/src/utils.c b/src/utils.c
index 9e0d5ca..73538ea 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -384,7 +384,17 @@ SYMBOL_EXPORT char* GetDataFilePath(struct Game* game, const char* filename) {
 
 #ifdef MAEMO5
 	char origfn[255] = "maemo5/";
-	strncat(origfn, filename, 246);
+	strncat(origfn, filename, 247);
+
+	result = TestDataFilePath(game, origfn);
+	if (result) {
+		return AddGarbage(game, result);
+	}
+#endif
+
+#ifdef __EMSCRIPTEN__
+	char origfn[255] = "emscripten/";
+	strncat(origfn, filename, 243);
 
 	result = TestDataFilePath(game, origfn);
 	if (result) {
@@ -398,14 +408,68 @@ SYMBOL_EXPORT char* GetDataFilePath(struct Game* game, const char* filename) {
 	if (sub) {
 		sub[0] = '.';
 		sub[1] = 'o';
-		sub[2] = 'g';
-		sub[3] = 'g';
+		sub[2] = 'p';
+		sub[3] = 'u';
+		sub[4] = 's';
+		sub[5] = 0;
+	}
+	result = TestDataFilePath(game, file);
+	if (result) {
+		return AddGarbage(game, result);
+	}
+
+	sub = strstr(file, ".png");
+	if (sub) {
+		sub[0] = '.';
+		sub[1] = 'w';
+		sub[2] = 'b';
+		sub[3] = 'p';
 		sub[4] = 0;
 	}
 	result = TestDataFilePath(game, file);
 	if (result) {
 		return AddGarbage(game, result);
 	}
+
+	sub = strstr(file, ".jpg");
+	if (sub) {
+		sub[0] = '.';
+		sub[1] = 'w';
+		sub[2] = 'b';
+		sub[3] = 'p';
+		sub[4] = 0;
+	}
+	result = TestDataFilePath(game, file);
+	if (result) {
+		return AddGarbage(game, result);
+	}
+
+	sub = strstr(file, ".JPG");
+	if (sub) {
+		sub[0] = '.';
+		sub[1] = 'w';
+		sub[2] = 'b';
+		sub[3] = 'p';
+		sub[4] = 0;
+	}
+	result = TestDataFilePath(game, file);
+	if (result) {
+		return AddGarbage(game, result);
+	}
+
+	sub = strstr(file, ".webp");
+	if (sub) {
+		sub[0] = '.';
+		sub[1] = 'w';
+		sub[2] = 'b';
+		sub[3] = 'p';
+		sub[4] = 0;
+	}
+	result = TestDataFilePath(game, file);
+	if (result) {
+		return AddGarbage(game, result);
+	}
+
 #endif
 
 	result = TestDataFilePath(game, filename);