Thanks for the detailed feedback, the goal we had in mind is to get required types/elements of slime (cats) into the goal pen which we displayed on the top right of each level. We opted out of text descriptions to keep a simpler experience and design overall where players would have to use their intuition and a few tries of figuring out the main mechanic to really get going!
Also yeah, some levels were simpler as we kinda put them together last minute, we had just enough time to get a somewhat working build with all the basic mechanics we wanted to display.
Thanks for the kind words and feedback, we will consider it all for our next games :)