Castlevania The Dracula X Chronicles US

[LunaMoo]

Well Spline actually isn't all that great, however is an upscaling filter and all upscaling filters in ppsspp are automatically setting rendering res to x1(5xBR also does that, however it's much better scaling effect might result in less blurry image) to then upscale it to display size. Bilinear filtering scales with rendering resolution making it less blurry the higher pixel density you render with, so whatever resolution you're using, since it's a 2D game it surely isn't doing much more than removing the blur ~ typically it's what people like through.

You should get similar result by disabling all post process and then setting rendering res to x1.