“The problem is that Brothers is neither particularly funny nor particularly moving. Harrelson and McConaughey are credited as co-creators of the series, which makes sense, because it plods along respectfully when it should be enjoying the mayhem. Even its showier scenes, such as an attempted stickup or a raucous rodeo, are unbearably steady. There are points at which the leads’ undeniable chemistry sings on screen, especially when they are learning the obligatory life lessons from one another, but Brothers cannot seem to work out whether it is a surreal comedy or a sentimental drama. Disappointingly, it settles on hovering somewhere in between.” 
Rebecca Nicholson, Financial Times 

“As a show it’s all over the place; what else was it ever going to be? Yet while some of the episodes – particularly a mid-season nadir when the two of them dress up in prosthetics and start a band – are right down there in zero-star territory, somehow the whole thing is held together by, yes, star power. Harrelson and McConaughey on screen together do have a magnetic energy, a friendship that works because it’s real. Sorry: “real”. Or whatever “real” means in the slipstream of TV shows like Brothers.” 
Benji Wilson, The Telegraph  

“It sounds inessential, and it is, but hock-bobbit and skippity-breakfast if this pair of toot-scootin’ Hollywood butt-nuts haven’t hit upon a tasty little comedy dynamic… Even better, though, are the supporting players…Such fine creations further down the cast show that Brothers is a bit more than two famous guys blithely horsing around, even if that’s what it ultimately boils down to. It’s a fun little trip.” 
Jack Seale, The Guardian