This is very nicely polished! The SFX are great, and I really like the clicking of each button press, it makes it kinda fun simply doing that.
Visually, it's all cohesive and looks great!
Having the countdown really amps up the intensity and makes you panic a bit, I think that's a great inclusion.
I wonder if you could do more to make it feel like you're a robber/hacker or whatever. Maybe have some intense music playing, or maybe a short animation before the round that has you zooming in on a vault or something. Maybe make the visuals a bit darker.
It'd be interesting if there was some way to bound the set of possible numbers. I found myself just doing "1234" and then "5678" then "90" in rounds 1, 2, and 3 every time to figure out the possible set of numbers. I don't know if that's the best thing to do, but it seemed to work alright, but wasn't exactly "fun".
Last thing I'd say is it'd be interesting if between rounds there were modifiers you could do to benefit you the next round (like additional time, eliminate a number off the bat). Or maybe a bonus if you complete it in fewer rounds.
Nice little game jam project!