In this project I looked into the similarities, and differences, in UI for various genres. This is my own take on an FPS hud.

From what I've seen, players want to be able to see as much of the screen as possible, so graphical queues are essential. Veteran users may find they don't want to take their focus of the edge of the game, while more casual players might need extra help to figure out what's happening, which is why health and ammo appear in the centre as well as the outside.

To create a sense of urgency, additional queues are added to make the player aware of their situation.