I would love to see ground traps like in PotD and HoH added!
Obviously not all of them, but the ones that turn you into frogs and (more importantly!) otters for a short period of time or the mines could be really fun to play around with, for example when you're building a dungeon/labyrinth-type of thing in your house. Or just to be a frog. Or an otter.
They could just work like little carpets when you place them!