I went to college in a very hilly town, and there were several building with multiple "ground floor" entrances. In fact, one was a favorite building during the winter. People would walk on the relatively flat low-land from the dorms to the Law building, and take the stairs or elevator INSIDE, and exit the other side of the building, rather than trying to walk up the ice-covered slope, or the treacherous outdoor stairs. It wasn't such a big thing in spring and fall, but summer (HEAT) and winter (cold and icy and slick as snot), and that building got very busy.
One building had entrances on three sides, all on different ground levels. I rather liked that one, from a safety standpoint. There were lots of emergency exits, and even at the top floor, you didn't have to go down ALL the stairs to get outside. Just one or two flights.
Of course, they did flatten the high ground of the campus, so they could have a nice flat quad, surrounded by the most important buildings. But the lower valley part of the campus just sort of dug into the side of the hill. It was pretty cool, actually.
If you can squelch the OCD - must be straight compulsion (hard to do, I know), then you can get some really nifty buildings.
Hmmmm, I wonder if you can make multi-level basements? After all, building a basement is just hollowing-out the foundation to the depth you want, and adding stairs and walls, so why not? Just digging deeper... Yeah, if you place your foundation starting at the highest level of ground, and then hollow out the inside, incrementally, it should be cheaper, and still give you plenty of workable space inside. With good lighting, windows won't be such a big deal. And actually, there may be cheats for that, as well. Sort of makes me want to place a lot on a steep hill, just to experiment a bit.