You cannot add HUD elements. However, you can “subtract” them by moving them off-screen. You can also change the look of elements by replacing their sprites. However, the sprite replacements will only take effect if they are loaded at the same time as the game itself (usually using a .bat file). Using sprite replacements, you can c reate a completely new use for static elements such as, for example, the SCORE word. You could turn that into an icon or something. The possibilities are fairly vast.