Vampire: The Masquerade - Bloodlines
In Vampire: The Masquerade - Bloodlines it's possible to disable the HUD with a console command. Console has to be enabled and the command (strangely not listed on the wiki page there) is draw_hud 0. Leaves you with contextual activation buttons and nothing else, it seems.
(Note though, my game/mouse always gets stuck after using the console so I also have to use the command chareditor after every other command which puts me on the skill screen where the mouse is usable again. This seems to be a common occurrence.)
According to the last post in this thread one can also bind these commands to keys by editing a config file - to avoid the console nonsense - but I haven't tried that myself. (The v_hidegui command mentioned there doesn't seem to be doing anything for me.)
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