I know this is a bit of an old post but I finally found something on detecting individual tiles like I mentioned. So what I would do with the information in this video is detect a 'slope tile' and then I would have the player or NPC etc. play a sloping animation as they move across the tile then reset the moment they're off it depending on the direction they're facing.

Hope this helps you out, knew there would be something out there just a matter of digging through the internet for it.