The login screen is a parodied Windows XP and the detail is perfect. The system is called "Modern OS" with a hand scrawled colourful logo, and the classic instruction "to begin, click your user name". Except the USER NAME is literally "Good Workers, Stay Productive", with a photo of roses as the avatar. You don't have a name, you ARE the slogan. That's an excellent visual joke and it tells you everything about the game in one screen.
The desktop is deliberately melancholy: a real sunset photo, purple and pink, pixelated and dithered, seen through a window with tree branches in silhouette. It's beautiful and sad, the view you won't enjoy because you'll be working until 21:00. The hand drawn icons finish it off.
And the taskbar clock IS the game clock: "Day 1 | Up next: Work until 21:00". Every action consumes hours. I clicked once and the clock jumped from 9:87 to 11:49, then to 13:33. Same as Employee of Forever, the resource you spend is your lifetime, and it's interesting that two independent entries in this jam arrived at the same metaphor. The task window is cruelly banal too: "Write 29 words in the Document 0/29", repeated three times, and you have to actually type them. Tedium as a mechanic, and it works.
Three notes. I didn't find the leaderboard, which is the premise of your description, in the first few minutes, so I assume it appears after a few days. The hand drawn icons are charming but don't say what they do, so I clicked everything to find out. And the clock reads "9:87", which isn't a time, so either it's a deliberate joke about distorted corporate time or a formatting bug, and I honestly couldn't tell which.
Burnout atmosphere built really well. Releasing the source under GPL-3.0 with documentation is also one of the strongest end of life answers in the jam.