Idle/Clickers aren't really my thing, but I can see that this is looking really polished. The pickup-range for the mouse either needs to be bigger, or upgradable.
Maybe to keep interest there should be rooms, rather than floors so you can explore in a way not so linear.
EDIT: I played it through and here are some more thoughts.
1. Keys are hard to come by. Even after I'd beaten the game I had dozens of quests uncompleted as silver keys also become far too expensive.
2. This was even worse for gold keys as after I'd beaten the end boss there seem to be no more gold keys.
3. You should get something for items that go to the trash.
4. The fruit machine at the end shouldn't be random. You should have a better chance of getting stuff. I only managed to get money (strawberries) and exp (bananas). Even after spending much more than I put in I couldn't get anything else.