How to implement 3d tile movement?

I am trying to make a game similar to the Thin Ice arcade game from Club Penguin. I am trying to get it so that my character snaps to a grid of tiles and moves one over when I press the appropriate key. How would I go about doing this? nothing I do seems to work the way I want it to…

So far the only real thing I’ve tried is snapping the current positions of all the actors to a grid using the Snap to grid node.