This is a neat concept and I like some of the mechanical twists that are later added in but I have to agree with another of the comments here, the difficulty level is through the roof at times. I'm currently on puzzle 27 and have been for a bit (edit: got to 28) but the final puzzles for each mechanic have almost universally been a bit harsher than is likely necessary. TBF I think the "count down & disappear" mechanic may just make it too difficult to visualize far enough ahead IMO.