“Labyrinth” as in the original Commodore PET game that did false 3D orthographic projection and incremental map movements? If so, then you don’t need any collision code. You make a 2D map which is just a [x,y] grid of shorts. in that grid, you have your short map to “what is here” and “where can I go.” Then if you try to go a direction that is not supported in the grid[x,y], you stop the user. Simple, no box2d, no physics, nada mate!