allright men, i FINALLY solved, when i open the html file everithing looks fine!
i share my process to future users with my same problem:
1)convert all audios to OGG files;
2)save your png files into webp files (backgrounds and scene objects mostly)
3)when you're export your game, leave unchecked "convert to webp", and don't scale to any other resolution!
Thanks to your help AFRLme, thank you, comunity!