Not Lords of Shadow, a proper Symphony of the Night style Metroidvania title?
Because it seems like it's been ages since the last one, and it'd be a really refreshing change from the hordes of mediocre FPS and Third Person Shooter clones flying around now.
If you search this forum for Castlevania and posts by me you'll find several lengthy rants about my distaste for Hideo Kojima's horrendous 're-imagining' of the series. Unfortunately, however, he has the rights to the series, sadly, so we may never again see another good Castlevania game.
I've never been any good at the castlevania games, so it doesn't really affect me if we get a new one or not. I did find the DS games fun, but couldn't actually beat it.
I should really play a Castlevania game... Are they tremendously difficult?
Depends on what version of the series. The NES/SNES play different than the PSX/GBA/DS versions and the PS2 are different than the PS3/360. The N64 are like betas for the PS2 ones.
