Yup, I didn't have time to finish these parts properly indeed. The cats were just my placeholder for obstacles, I didn't have time to replace them with more appropriate assets.
As for the connection display, yeah I wanted to use shaders to fill the pipes progressively, but I spent a lot of time trying and didn't manage anything decent enough :/ Also the pipes are only supposed to fill once the exit is reached, however it does sound like a good idea to make them look a bit different as well depending on whether they're connected or not. Maybe make the connected pipes brighter or something.
Thanks for playing and for the feedback :)