Some people said that LOS "oozes SCV4".
That was me a while back actually. That was an overstatement though, as I later confessed in that same thread.
The whole first half of IV takes place in outdoor areas. There is a swamp, caves, waterfalls, towers (not outdoors I know, but still before the castle) and such. All of these things are present in LoS, and before the castle. In addition to that, there are cool things like the return of whip swinging(why has that not been in many Castlevania games? That still baffles me). In those areas, I feel they share a lot of atmosphere. My opinion though, I guess.
There are plenty of references to other games(I'm not talking about name drops) as well. Some of the whip combos are performed exactly the same way they were in LoI. Vampires look like more detailed versions of the vampires in the N64 games. There is a maze garden, reminiscent of the one in the Villa stage in 64 and LoD as well. If you look at him from the side, Gabriel moves and jumps a lot like Richter's sprite. When running, he looks like he's doing a more applicable version of the Belmont strut(though not when he's walking, sadly)! He's got the Belmont posture when standing still.
The game has zombies, skeletons, armors, bats (only during the Carmilla fight, but they're there. Yes, I wish they were in the levels too.), flying imps, crows(though not as enemies for the most part), wargs, werewolves, swordmaster ghosts(from LoI and CoD), and mandragoras. ALL of those enemies are from past Castlevanias, some in more than others. I probably missed one or two, but I think that should be most of them.
After you kill Carmilla it kind of takes off on its own though, but most of the game is over at that point. Forgotten one was a neat reference to the Forgotten One in LoI, as you had to fight from his feet to his head, in that order. Also, it takes place after you've completed the game.
In this case though, I really feel like it shouldn't have been DLC. The Forgotten One levels were really fun though.
Anyway, some of you now think I'm a raving lunatic, and others may actually agree with me to some extent. I just get a bit fed up with the criticism the game gets, and try to defend my views on it from time to time. Just thought I'd put my... $1.04 in. Way too much text to be 2 cents. Yay videogames.