I made a quick Escape-the-Room game at Scribble (a weekly Creative Conversations Club). It's not digital so you can't play it, unless you come and borrow the physical copy from me. But here is what it looked like:
Not pictured: A 30cm ruler.
The padlocks are not clues, they are meant to represent real padlocks and when players know the right combination, they unlock additional clues:
Opening the red padlock ends the game. (Or, in the revised edition, it leads to the final superpuzzle! Also not pictured.)