Do the enemies collide with each other? If so, how does it remain performant? Does it leverage DOTS? Burst? Jobs? ECS?
The whole innovation of Vampire Survivors wasn't the gameplay design, it was the implementation. Thousands of enemies all colliding with each other, to the point where tidal waves of bats would suddenly bulldoze werewolves into the player.
Looking at these gifs, I see very sparse ground-based enemies and large swarms of airborne enemies that don't collide with each other.
Can you please explicitly tell us whether or not "large swarms of enemies bumping into each other" is a feature you delivered?
Because that's pretty much the killer feature that made Vampire Survivors special. It's the secret sauce. Everything else in the game is just a bunch of remedial action game mechanics and basic UI elements that I either already know how to implement in Unity, or could easily look up.