You can go into the negative by clicking really fast on the buy buttons. Is that intentional?

The panel on the right that shows how many tappers you have takes up a lot of space unnecessarily. that info could be on the shop as well.

You don't have commas separating big numbers ( 1,000,000 instead of 1000000 ), you should! makes it easier to read.

Is there a roadmap? Where do you want to go with this game?

Hello! Thank you for telling me all of this. The negative issue I will probably fix soon and the panel on the side will definitely be changed as I have also found that issue with it. Instead of the commas I might instead do stuff like 1M and 2B. My plan for the game is to try to make the UI a lot nicer such as the shop and amount area.