Unfortunately, the health bar and and the main GUI elements are hardcoded and there's no way to remove them via the code. So your only option would be using a transparent texture to cover them. Most other meshes can easily be hidden via setting a "0" mesh in module_meshes though. Also if you'd like to hide the chat, you can either mute the players by the in-game menu or a more fun way is via the Module System. You can create a script that is triggered on player_joined if you're working server-sidely or looped every 10 seconds on your client. If you chose to do it server-side, you'd have to type something like
(player_set_is_muted, ":player_id", 1),
And all the players would get muted once they join the server. Or, client-sidely you'd have to run a loop through all players every X seconds (We're just looping since new players could be joining, and they wouldnt get muted if you just did it once) and mute them all. So something like
multiplayer_server_st3fan_mute_players = 10, 0, 0, [(multiplayer_is_server),],
[
(try_for_range, ":all_players_ids", 1, multiplayer_player_loops_end),
(player_is_active, ":all_players_ids"),
(player_set_is_muted, ":all_players_ids", 1),
(try_end),
])
Then all you've got to do is append the trigger's name to the list of triggers run on your client (CTRL + F for #mm), compile and finally you'll get rid of players' chat.
