Love-hate relationship with this one.
On one hand checkpoints, enemy placements and stiff movement and controls make it a slog at points with difficulty being artificially spiked through unfair means.

Yet for an NES game it has gorgeous 8bit environments and set pieces, where the game designers clearly tried to do something with the set design and art direction, an abitious mutli-route system, a plethora of smaller mechanics and systems and some fire music.

It all culminates in Castlevania III being the best out of the NES titles and worth a shot if you're willing to deal with some outdated gameplay.