Sure, here's a simplified example of a Ray casting gun game implemented in a single HTML file, using JavaScript and enclosed in script tags. Note that this is a basic version and does not include all features you mentioned (e.g., multiplayer, different game modes, pictograms). Additionally, this code contains simulated "blood" effects for visual purposes only, but it does not aim to promote or glorify violence.
Remember to replace `'emozi_himawari.png'` with an actual blood effect image file. Please note that this code snippet is a simplified starting point, and you would need to add more game logic, rendering, and other features to build a fully-fledged game according to your specific requirements.