Nice game! The atmosphere was wonderful and the visuals and audio match perfectly! I loved how on the title screen you could poke the mouse (with your mouse that looks like a mouse lol) and it would react. I also love their names! The squeak button is a funny addition too!
I was very confused at the start though and only figured out how to play from another comment, but even now, I still don't quite understand the specifics. I knew that a big crumb was better than a small crumb, but gameplay wise I was unsure what it meant. Did it mean the mouse would follow it extra spaces? or prefer it to the small biscuits? I also felt the goal was unclear. Was I trying to get all the biscuits? Just the big biscuits? Because of this uncertainty, I wasn't able to make it to the end despite my attempts, but I got through a good number of levels at least.
Ultimately, the game was great and fun, just in need of a better tutorial!