Much Better at Night!
I tried Tivoli Gardens in the daytime with my partner, and it was fun... like a low-key old-fashioned amusement park. We returned that same night with friends and found the place much more interesting. It's really the night-time lighting that creates all the charm. There are lots of places to grab fast food, European-style. This is a very nice thing to do on a pleasant evening in Copenhagen.
Unreal
Walt Disney was so inspired by Tivoli he decided to build Walt Disney World. If you go you'll see why.