Let off some steam (and missiles and grenades and air strikes and lasers and exploding rotisserie chickens), Bennett
Most people would say that Broforce's strength lies in it's fusion of Metal Slug style run-and-gun with the sheer chaos that comes from its constant chain reactions of gigantic explosions and destructible terrain along with the huge, diverse cast of characters, each equipped with unique and completely over-the-top firepower.
They may also say that the equally huge and diverse cast of enemies allows for interesting encounters, especially as the enemies grow more and more ridiculous alongside the plot (which also grows more and more ridiculous).
Many people may say that Broforce's mechanic of tying extra lives to switching your character compels players to unleash their hugely destructive secondary weapons regularly, lest they lose that ammo once they switch over to the next Bro they've rescued. These people would probably suggest that this mechanic elegantly contributes to those mentioned chain reactions of gigantic explosions and destructible terrain, essentially demanding that the player turn every firefight into an absolute mess of total carnage.
In the end, these people would say that this points right to the true strength of Broforce: A well-tuned system guaranteed to create unpredictable Rube Goldberg machines of blood, explosions, flying propane tanks, falling rocks, and plenty of bullets inside plenty of terrorists. While there may be lots of unforeseen consequences that would force you to restart your level over and over, these people would say that this only helps the game's case - even your deaths in Broforce are as ridiculous as your kills.
Unfortunately, these people would be wrong. Broforce's strength lies in the chat system that lets you send action movie one liners on demand.