The levels in Vampire Survivors do have bounds but depending on the level it might be a giant open space or sectioned off or themed in some way. The level from the first DLC, for instance, has some open grass areas, a forest, a village, a lake...and maybe something I can't remember lol. There are also relics to pick up in most levels that give you permanent upgrades or unlock weapons or characters as well as items to help in that particular run. There is a lot to find and uncover in this game! Are you playing it now too?