I am definetely working on adding variety and making the game fun for a longer time. I definetely will introduce features that will adress the problem you mentioned.
Hey :) With the merge monetizer every time two bubbles merge you get a certain amount of money based on the size of the bubbles. I don't really know the details how it is calculated anymore but that's the idea of it at least. Just tested and it works.
Thank You! I will definitely add more content in the next couple of days and weeks! I already have some ideas written down but I have to do a lot of code cleanup first.