already tried.. but the result is pixellated
If you mean by "pixelated" that it's not anti-aliasing/blurring, that's by design. It's simply zooming in, it's not actually changing the graphics. Think of it as just leaning forward. The graphics don't change but for Knytt Stories I think it makes a huge difference to zoom because each screen becomes so much more readable which in many cases improves the graphics tremendously from a relative perspective. Like looking at a piece of art from across the room as opposed to being able to examine it from steps away.
If you mean "pixelated" in a sense that it makes certain things blurry that's inevitable for levels that incorporate elements that are already trying to anti-alias by blurring edges of a graphical element to make it look more natural. So certain elements, I've noticed, take the tomatoes in Vegetal Gibber's level or the text I use in Hypnagogia (et al), might look worse with the zoom because the edges of the tomatoes or the text are anti-aliased and look fine without a zoom, maybe even better, but a zoom makes the edge blurriness more and more obvious. Ironically, maybe in your case only, using the zoom makes levels that actually incorporate elements that you want (such as anti-aliasing) end up being hindered aesthetically by the zoom effect. But I think it's still offset in most situations by the value of being able to see things so much more clearly.