A gaming machine arranged to display a symbol in each element of a matrix of elements; each column of elements of said matrix of elements comprising a portion of a simulated rotatable reel and wherein at an occurrence of a trigger event at end of play of a main game; (a) said main game is completed and any prize is awarded, (b) at least one feature game may be awarded wherein each said rotatable reel is caused to be spun and brought to rest to display elements of said matrix in a first stage; said first stage displaying symbols in elements of at least one said column and uniform imagery in elements of each remaining said column; said feature game then progressing to a further stage wherein elements with said uniform imagery are populated by symbols of said elements of said at least one column.