Brilliant puzzle design. I've been stuck on the level with two red circles for about an hour but I'm still determined. Perhaps it is the simplicity of the puzzles that keeps me enticed.
Shortly after this I tried pushing the big chunk into a wall and the game crashed :( with this error:
ERROR in action number 1 of Other Event: User Defined 2 for object obj_block: PerformEvent recursion depth failure - check for infinite loops, check objects for parenting at gml_Object_obj_block_Other_12