Bullet heaven is what we're apparently calling the Vampire Survivors-like genre, because the only decent competing name was "auto shooter survival" and unfortunately the acronym for that is "ass". Spitfire Interactive, the developers of Hordes of Fate, are splitting the difference with "bullet heaven auto shooter", but you know what kind of game it is: a roguelike where you gear up a hero then set them loose to auto-attack endless monsters, upgrading as you go.
Hordes of Fate has the pedigree of Defiant Development behind it, the developers of the Hand of Fate roguelikes, and boasts that it's coming from "the original creative team." (Spitfire Interactive was also responsible for superhero tactics game Capes last year.)