Castlevania: Dawn of Sorrow (2005), the first installment of Castlevania on the Nintendo DS, is a direct sequel to GBA hit Castlevania: Aria of Sorrow. In it, Soma Cruz continues to cultivate his unhealthy obsession with collecting the souls of his enemies.
Using the powers that only tool assistance can provide, every single possible soul is collected in a bit over 35 minutes. If you've ever played the game, you know what a pain those souls can be.
Very detailed information on the run is available in the author's comments.
There are also runs that complete the game as fast as possible with Soma, with Julius, and with Julius while staying in bounds.