Daytime: what a delightful wacky song! It has a nice interesting beat to it, and gives time for me to wrap my head around it. Feels really pinball-y. Not much variation, but plenty of it. And then again, we also have...:
Nighttime: I am used to night-time themes being a softer version of the daytime - this is an entirely different theme, which is interesting. It feels as if this is the time when the hardcores come out to master the games, soft colorful light lighting up the city. It could use a bit of variation, as the 'bleep-y' bass sound does hurt my ear after a little while, and the theme does become repetitive (it is 2:46 of almost no change).
Overall: nice quality, fits the theme (and city) well! Just wish there was a bit more variation.