I think this episode gave the series a chance to breath some love. The genuine affection between all the characters is what saves this show.

Kirsten Dunst's work in her scene in the back of the patrol car was amazing.

Quibbling about weather balloon physics is like debating which species
of swallow can carry a coconut. Neither can, but that's never the point
of a whale of a tale. Gotham exists in a comic book universe that while
recognizable is a bit off. Accept the premise and Gotham works or you;
don't, and it doesn't.