g2222: "a sci-fi, action-packed, bullet heaven roguelike" I didn't know what "bullet heaven" meant, so I googled it.
In a nutshell: This description is pretty misleading. Some call it the opposite or "reverse" of bullet-hell, so basically no incoming bullets at all. Instead, it's another Vampire Survivors clone. A horde / wave shooter against ever growing numbers of enemies.
GOG apparently doesn't know the difference either, because they tagged this game as "bullet hell" regardless. A "Survivors-like" tag doesn't seem to exist yet.
None of the potential tags/genre names seems ideal, but I think at this point bullet heaven is very much the leader.
The logic being that instead of dealing with enemies that shoot a lot at you in predictable patterns that depend on the enemy type and often practically fill the screen in hard to avoid damaging shots (bullet hell), you're the one who shot a lot around you to fill the screen in patterns that depend on the weapon/s loadout you have. So the screen still gets filled with shots, but those aren't ones that are very dangerous to you, but instead are dangerous to the enemies. Still "bullet" but opposite of what the bullets do in "-hell", ergo "heaven".
A lot of these still get tagged/listed as "bullet hell", not only on GOG. And, frankly, I get it. Because in all of these, while technically you're the one filling the screen with "bullets", there are a lot of enemies, by the end of levels with constant huge waves of enemies that fill the screen, and can be very hard to avoid and not die by being overwhelmed. Which is, well, about the same as what happens in bullet hell games.
The enemies don't shoot bullet, but they're not that different from those bullets themselves. So most "bullet heaven" games do fit very well with what makes "bullet hell" games be "bullet hell", apart from the (admittedly important) part where instead of mainly moving to weave around/between the bullets (which you still do) you mainly try to get to that stage with matching loadout yourself so your own weapons/gear/bullets will remove enough of the enemies to prevent them from overwhelming you.
"Bullet hell" isn't a perfect match, but is still a pretty good one (and more than how many tags/genres match a lot of sort-of-mostly-that games). I think the only downside of marking bullet-heaven games as also bullet-hell is that, so far, bullet-heaven kind of includes the bullet-hell elements in it, so it's not necessary. But by that logic almost every metroidvania shouldn't be also tagged as platformer, yet it understandably seems perfectly fine to almost everyone when most of them do.
As for survivors-like, while technically true, I find the term always confusing even though I know what it's supposed to refer to, because "survival" is a (very wide, but still) genre.
It's also a genre naming convention that is relatively rare, apart from the (by now widely abused and ridiculously stretched) rogue-like genre, nobody does that for practically no other genre. And even though Vampire Survivors is still fairly new, I'm sure there are lots of people who played multiple bullet-heaven games and still don't really know Vampire Survivors, plus there already were/are lots of unrelated games (of different types/genres) with "survivor" in the name. When rogue-like became a thing you could have realistically gotten a good answer to "what game is Rogue?" even without context. You can't do that with "What game is Survivor?", there are a ton of earlier games with "survivor" in the name, and Vampire Survivors is itself not a game called "Survivor".
