The ghosts occasionally do not move. This is intentional, it simulates speed in the full game.
Blinky, the red ghost, may occasionally skip a tile later in the game. In the original, Blinky would move at 105% speed, in this version there is a 5% chance he'll move twice.

-- Grid --

SCORE 0

C C C C C O

*note: ghosts some times dont move or move twice,
this is to emulate the speed of the ghosts in the real game