Some of the not quite 90 slopes seem to be due to arrows representing more of topological structure not necessarily accurate geometric representation. Could be elevators with doors on both sides, connect doors on opposite sides and you will get a bit of slope. Some of them might spiral stairways. The vertical spacing between floors is likely also exaggerated for clarity. Underground there might be larger gaps since the train tunnels need to go over each other under the rivers and what not, but there is no way 3 above ground floors (4f-2f) have empty gap 5x the ceiling height of individual floor.