PS2
Castlevania: Lament of Innocence
About 7 1/2 hours to beat end boss; Got about 90% of all secrets. If I wanted to 100%, it would probably take an extra hour. Only did one playthrough.
By the way, fun game. Story is weird, but gameplay is pretty fun. Not too frustrating, decent whip combos and nice music. Read some reviews that it's too short, but I like the length. If you want to extend the replay value, there are extra characters with different powers to unlock.