Mouve your mouse pointer around and play with this special grid! ;D Space to acces setting (Try to set the "coloring mode" var to 1!), P to pause and R to reset all the all points of the grid to theirs initial positions (note that it enable pause so press p after it).
All coding by me! -made in mhh...well 2 days!!- (Credit to nintendo for probably one of the most well known power ups in Super Mario Bros ! :P)