the DS games are full of bad art. If you want to learn the style they degenerated from look for SOTN sprites.
Actually some of the DS sprites are pretty decent; I rather enjoy Soma's spritesheet from DoS myself. Most of the others are pretty bad, though.
In general Castlevania is a very mixed bag. Environments especially are usually quite ugly and look like they took five different tilesets and cobbled them all togetherp
I do not think that we are playing the same castlevanias.