Of course first parts when I tried to use the either 2nd or 3rd door it didn't show up the 'Z' and my character started shaking.
Hope you find the issue if there are any
Viewing post in Temple of the Shifting Gears jam comments
I checked it on browser version and on my PC, it's true the "Z" doesn't show up for the 2nd door with gear mechanism. But instead a lock symbol shows up when the door is locked. And the third door is working just fine when you unlock it by killing the first monster, the "Z" shows up on both my PC and the version I uploaded.