They tried to make the both medical and firefighter action scenes seem exciting or dangerous using dialogue, instead of using appropriate stage props, cgi, or direction to the actors. For example firefighters had a fight over a cat stuck 7 feet up in a tree, where one firefighter refused to climb up the 5 or 6 steps to untangle it's leash, cause "cats have 9 lives, I only have one!" A 6 feet fall onto grass isn't going to kill anyone. Lifting a piece of rubble off a guy's legs when a mild aftershock was coming caused another argument about risking multiple firefighters' lives to save his legs, although there was minimal rubble around and they only had to lift something and pull him out.
Most of the actors played their roles decently, so can't really blame them. The romance was obviously meant to carry the drama, but sadly the FL was lacking in conveying emotion and progression of all romances was oddly disjointed due to poor script and bad editing. Not even sure why the couples like each other, they just suddenly became couples with a few minutes of interaction scattered throughout the initial episodes. It seems like they tried to cram in everything they could, so there is not much time spent on how things all develop. Those that didn't get along are suddenly friends(ML and other firefighters. ML and SML, FL and female Dr love rival) or lovers (the rookie and the squad leader, nurse and firefighter), so it's hard for viewers to connect with the romances or brotherhood emotionally. Overall bad editing, writing, and poor directing choices make it a difficult, somewhat boring watch, even for someone like me that is purely looking for entertainment and willing to overlook flaws in logic, plot, cgi, etc.
Gong Jun just couldn't save it no matter how charming he was.