How do I stop from going backwards on a layout?

Like those old arcade games where once you advanced forward you couldn't go back?

My first thought was to just keep moving the location of an invisible solid object....

Something I missed in the manual?

You could do a "LevelwallX" variable that changes when the screen moves. If Player.X is less than Levelwall set Player Xposition to "LevelwallX".

So if the coordinates for the player go behind the LevelwallX variable you have set up, it will just "teleport" the player back to the wall.