Make character walk on walls defying gravity in a 2D Game

Im usually make games in unity,but since I’m making a pure 2d game i tried working on stencil,but after weeks i think the visual programming system isn’t enough to do what im trying,so i want to know if with unity its possible

Im trying to make a game like lemmings,several characters walk from left to right and walk alongside the walls defying gravity,making their walk with waypoints would be easy,but the catch is that the scenery is destructible,the structures are like lego pieces and change all the time,so no invisible colliders,no waypoints,i need a way to make all the logic work just in the characters,maybe with ray cast in four directions and changing movement based on which ones collided ?

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Yes, you can make what is being considered a 2.5D game in unity it will all be in 3d space but using 2d items you can accomplish this with a scrolling camera or with the onGUI function. Use the simplicity of 3d space with colliders but in a 2d appearance.