
In a retrospective review of the album, Craig Hayes from wrote that Countdown to Extinction's 'status as a gateway metal album is indisputable' and its 'popularity speaks volumes about its significance in the metal canon'. In the liner notes of the album's 20th anniversary edition, music journalist Kory Grow wrote that 'thanks to a perfect balance of hard-rock song structures, epic choruses, and fleet-fingered guitar work, Countdown to Extinction became an instant classic, benefiting from copious and radio play.' Editor in chief Rick Florino called the album a 'seminal' release and commented that it 'changed the game by preserving the band's thrash intensity and impressive technical prowess, while dropping some of the biggest hooks the genre had ever seen'.
