The alpha will be available to download on PS4 and PC today starting at 9 AM PDT / 12 Noon EDT / 4 PM GMT. If you preordered a copy of the game, you're guaranteed a spot. The alpha ends on Sunday, November 2.
2K Games and developer Turtle Rock Studios have also released a new "Kraken Interactive Trailer" for Evolve, which you can see below. It allows you to see a match unfold from five different perspectives.
Evolve was originally targeted to launch this year, but it was recently delayed to February 10, 2015. The game's developer, Turtle Rock, also created the Left 4 Dead series. In Evolve, four players fight together to take down a fifth player, who takes on the role of a monster with unique (and deadly) attributes.