You could definitely build underground in the original game. I only ever had the original one when growing up and did stuff underground a fair bit. One of the

You could definitely build underground in the original game. I only ever had the original one when growing up and did stuff underground a fair bit. One of the early campaign parks came with a bunch of rides and stuff underground off the bat. I think there were some practical changes to make it a bit easier in RCT2, but it was never hard.