Hey, thanks for playing and for the detailed feedback, really appreciate it!
I was wanting everything to feel "analogue", hence the clacky keys and physically pulling levers/twisting valves with the mouse, but appreciate that it makes things a little unwieldy. That's partly intentional, but it's not designed to get in the way of progression, so I'll definitely take that on board.
The reason everything uses the numpad is down to inheritance, it meant I could set up a base machine class that all machines derive from, and it allowed me to create lots of usable machines that have the same basic "numpad and mouse" controls in a short space of time. That's why the shooting minigame also uses the same controls, though you're right that it's not the most intuitive method.
My guess as to why it failed you is because you didn't clock back out, which is something other players have said they didn't realise they needed to do. Definitely should've included a prompt that said you'd collected enough slime for the day and could clock back out, that's on me!
Thanks again for the honest feedback.