I found a great little trick within your Team Fortress 2 settings to customize your in-game GUI. Basically, it takes your current HUD (In-Game GUI) and makes it a minimal as possible. This helps see more of the game and less of the “cartoony” hud.

Here is where you can access the option to enable it:
Options > Multiplayer > Enable Minimal HUD

Maximum HUD:
Click to view image.

Minimal HUD:
Click to view image.