Very charming, nice job! Especially for a one-person job this is a really impressive effort. I really like the theme and overall vibe, and the concept for the game. I finished it all the way to the fina heist.
Watching the challenge percentages get easier as your mice improve is great, that feels like good progression. I also like how you handled potentially getting caught, with the attention meter at the top and there being an increasing chance of failure. My strategy was to just keep clicking on the same mice to make sure they levelled up fast.
I don't have much feedback, I think I'd have to sit with it a lot longer for that and it's a great project for the time it's taken as is. Maybe I'd have liked a few more sound effects here and there.
I think the biggest thing is that it would be nice to have reason to be more thoughtful about which mice im sending. Because they level up quickly and across the board, and because the jobs don't have a main-challenge type attached to it, i end up just clicking whoever and waiting until they get good. It would be nice to have reason to think about my decisions and care about levelling specific mice up and hiring mice with specific attributes, because right now I think I can get through just fine by mashing buttons and hoping for the best.
(That being said, I tried a similar thing in our project and didn't get it implemented in time either :P )
If like other feedback has said you can find a way to make the challenges involve the player a bit more and add a bit more of a mechanic there, I think it's a really solid game loop!
Great work!