Thank you so much for playing the game and your warm message. I makes my day that there are people liking my game. I really appreciate it and I am grateful for the detailed feedback.
To be honest the majority of the assets comes from a single pack and only a few from the rest plus a couple I model myself. I am comfortable with blender so occasionally I add/remove polygons, unwrap again on different textures, using the same materials from a single pack, I increase the saturation to other materials etc. Pretty much that's my workflow.
About the puzzles, yes I know what you mean and you are 100% right with it. I had myself more fun testing the last levels.
Again thank you very much for giving my game a try. :)