A number and a graphic representation of the player’s health is ideal if the player character has a high number of health points. This lets players assess their health as a percentage at a quick glance, while getting more precise information about how much damage they are taking.
Show acceleration through animation
Numbers alone don’t show acceleration very well, so a graphic such as a bar or row of hearts show how quickly a player is losing health without them having to do much mental math.
Multisensory & diegetic health displays
Make sure you’re using audio to reflect health loss and gain too, so players with low or no vision can tell when they’re taking damage. This helps all players focus on the gameplay instead of looking at the UI, too. With a little creativity, there are clever ways to indicate health diegetically without using a HUD element (think Super Mario Bros., where Mario gets smaller when he takes a hit).
For secondary stats, like experience points, mana, stamina, ammo, etc., displaying a graphic representation and a number is also ideal so that players can keep their focus on the game. Bars are a classic way of showing this, but consider more creative solutions too, like dials, ammo clips, piles of coins, and so on.
Multisensory & diegetic statistics
For extra immersion, think of ways you can indicate secondary stats diegetically (within the game itself) instead of on the HUD, especially if you have lots of them. Can you visually express a character’s stamina by showing them getting tired and panting, rather than representing it with a bar?
How important is the score in your game? Is it something better left to the results screen, so players feel more immersed in the game? Or are combos and multipliers a huge part of gameplay? Design the size and prominence of score elements according to how important they are to gameplay.
If score is important to your game, make sure to double down and feedback and use audio to let the player know how they're doing, like ascending musical notes or louder sound effects when the player scores big combos, or using a voiceover to cheer them on.
Like other stats, it’s easier to read a visual timer than a numeric one. Use animations and juice to let players know when time is about to run out. Think about what the timer could represent in the game world: a dynamite fuse, a kettle coming to boil, the day/night cycle, etc.
Ticking sounds are trite and can be annoying to many players, so you may be better off creatively incorporating sound into your in-game environment instead.
Ideally, players should be able to customize the size, shape, and color of the crosshair in the menu. Not only does this benefit the pro players who are playing your game with maximum efficiency in mind, it helps new players and players with low vision see where they’re aiming when they can choose a big crosshair.
Crosshair as Compact HUD
Vary the crosshair thickness, color, and shape to indicate the spray radius, recoil amount, cooldown or other statistics for unique weapons in your game. You can animate the crosshair to indicate hits, critical hits, or other actions too, since the player’s eyes are generally focused on the center of the screen anyway.
The style of your game’s pointers and cursors are an opportunity to reflect the style of the game in the UI as well as show the player which actions they can take.
Make sure your pointers indicate exactly where the user is expecting to point -- otherwise, players may find the accuracy of your pointers to be frustrating and buggy. If your cursor is a dot, how big is the dot’s hitbox? Are your players accidentally clicking on things in user testing?
Cursor as Compact HUD
Creatively, you can have multiple cursors to indicate different actions. Just like how hovering over links changes the user’s cursor to a hand in a web browser, think about how else you can give the user feedback about which UI items and in-game objects they can and can’t interact with. Always include audio and visual feedback so the player knows when their input succeeds or fails.
Accessibility & Compatibility
Ideally, players can customize the size of pointers and cursors so players with low or no vision can see the cursor. This also benefits players using high-resolution monitors, who often suffer poorly-scaled, tiny UI. Be careful about relying on the cursor as the sole visual indicator of action if you’re going cross-platform, since mobile games with touch input don’t generally have cursors.