Heads up displays are the thing that tell you about how much health you have or what items you can use (usually both). This makes them essential to game-play and a bad one can really annoy a player. If your HUD is bad or is not to your liking, some games give you the option to make your own or change the existing one, TF2 does this and many people have made their own custom HUD’s available to download, I tried making one myself and it isn’t too hard, but it does take a bit of time to understand. CS:GO allows for less customization, only allowing you to change the colour of aspects of the HUD, but it also allows for cross-hair customization. StepMania has an amazing level of customization, I haven’t looked into how it works but the amount of different themes that are made by the community is astounding. you can change pretty much anything and use custom made textures and such, there is so much customization. These are just a few of the games that allow for truly custom HUD’s.
So why have more recent games had less customizeable HUD’s? Well, it’s hard to implement, and if you are developing a game like COD, which comes out every year, you’re not really going for customization, you’re going for new maps and gun models and stuff like that. Also these customization’s are technically mods, a modification to the game, some of which could make the game easier to play. so in the case of CS:GO where its a hardcore E-sport, this could make people mad about the legit-ness of someones play. TF2 is a very competitive game, but just not as much as CS:GO, so the customization is more of a preference and many people have different preferences, I personally use broesell HUD. Also TF2 is more movement based and also gives you the option to turn off view-models (i.e the gun you see in first person) so you can see more on the screen, CS:GO doesn’t give you this option. So CS:GO is less customizeable than TF2 because of CS:GO’s more serious attempt at E-sports and TF2 has more customize-able stuff because of its less competitive nature in E-sports.
Where does Stepmania come into this? Well Stepmania is a rhythm game, with a butt-load of customization. You can change everything from the notes on the screen to the sound when scrolling through the menus. The level of customization is insane and I would highly recommend looking up some of the Stepmania themes and noteskins just to see how varied they are. Some of them are made for game-play and some of them are made for looks. I’ve heard that osu! has a similar level of customization but I don’t really play osu! so… yea