Level  25 is not solvable -- 2 yamyams ([11,25] and [37,29]) are "loose" and eat diamonds ([9,19]; [16,17]; [43,25]; others) before they can be reached, and/or knock loose other yamyams
Level  27 is not solvable -- spaceship ("tank" according to splash screen) in wrong place
Level  76 is misconstructed -- robot room nearly impassable because bombs tip over or robot below column of emeralds moves, disturbing path.  I had to try 20+ different pause lengths before I found one that worked.
