I played this through the PS4 remaster collection, and I'm actually surprised by how well this game held up. The controls are quite tight, the combat feels as intense as you would expect from Castlevania, and of course, the enemies and level design can be very nasty. The difficulty is pretty forgiving in the first few levels, but the last few levels are borderline insane, as they take the level design gimmicks from the earlier levels and ramp things up to eleven. Also, there are definitely more trickier boss fights in the second half of the game. Thank god for save states.

A new aspect that is introduced for the first time in the series is the character switching mechanic. The game allows you to choose between branching parts in some places, and you can meet three characters, and bring one of them with you. Their individual gameplay are quite distinct. For example, one of them can climb walls and ceilings to access normally unaccessible areas, and there's a mage that can use powerful spells which will help you beat the bosses far more quickly (Sypha best girl!). There's also different endings depending on who's with you to the very end. The endings aren't that different from one another, but they're still a very neat addition.

In terms of being a sequel, this game pretty much nails it. The new mechanics makes the game feel more dynamic and varied, and the level design are overall more interesting than the previous games. Obviously there are NES-era game design aspects that makes for some frustrating moments, but the game is still a blast to go through.

Lastly, the soundtrack is a banger for the most part. It makes dying over and over in the same area feel much less annoying.