Tile based pacman game

I am trying to make a pacman game and was advised that collision detection for a game like this is much easier if you create it using a tile based methodology. I have the map created and the character moves fine around the grid. But once I added collision detection it seems to be a bit off and inconsistent. Im not entirely sure what the problem is with the collisions.

Could some one please have a look and point me in the right direction

Thanks