Yesterday was my project exhibition and my ending of game wasnt too much awsome as compared to my starting so i set the code in that manner that noone can be able to finish it without changing the code
The trick to HUD is making the items so small and close to the camera that you need to move it by .0001 meters each time and it would still be too much. That way, if the user happened to look very closely into the ground or at a wall, the HUD won't disappear.